ODHXER : AFRICAX LAND SHELLS. 19

NEW OR LITTLE KNOWN AFRICAN LAND SHELLS. By NILS HJ. ODHNER, Stockholm. (Communicated by Major M. Connolly.) Head 13th November, 1931. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 [PLATE 2.] FROM the collections of African land shells stored in the Swedish State Museum I describe here three new species, one, Homorus connollyi, from East Africa,. the others, Opeas costellatum and Connollya (n. gen.) camerunensis from Camerun. The two latter species belong to the collection once possessed by the late Mr. A. d'Ailly, but were not described by him in his work of 1896 * nor later, since he was in hesitation as to their systematic position Besides describing these new species, I use this opportunity for publishing photographs of the few remaining Camerun shells described by d'Ailly in 1896 (except Helicarion depressus, which could not be recovered) but which have not been illustrated. In some otheT cases I have given particulars as to radula and other anatomical characters of systematic importance. PEDIPES DOHRXI d'Ailly. (Plate 2, fig. 1.) Since the original diagnosis of this species is excellent, I have to add only a figure of the shell showing the chief characteristics implied in the shape, in the close striae and in the dentition of the aperture. In the two first respects it differs from the West African P. afer. A further difference is offered by the radula, which was examined in a specimen 4 mm. in height. The radula measures 1 mm. in length and 0-7 mm. in breadth and contains about 170 rows of teeth, which amount to no less than 300 on each side of the rhachidian tooth. The innermost, about 100 laterals, are so crowded that there are 13 or 14 in a space of 0*01 mm.; they measure only 0-007 mm. in length. The marginals are somewhat larger and more distant, about 6 in the same space. Though the number of teeth thus exceeds that of P. afer and P. unisulcatus, their shape is similar (cf. Odhner, 1925, pi. 9, figs. 14, 15).2 STREPTOSTELE BucnuoLzi von Martens, and EDEXTULINA MARTEXSI, Smith. D'Ailly described (1896) a new species of the genus Streptostele under the name of pusilla. This is a distinct and valid species, and the diagnosis should only be completed by a figure of the shell; this is given in Plate 2, fig. 2. Since only two small specimens of this species are in the collection, a thorough study of the specific or generic characters cannot be made. 1 Contrib. a la connaissance des mollusqucs terrestres ct d'eau douce de Kameroun. Bih. K. Sv. Vet.-Akad. IlandL, vol. 22, iv, 2. Stockholm. 2 Marinula juanensis n. sp. ncbst Bemcrkungcn fiber die Systematik der Ellobiiden. Arkivj. Zooloyi, vol. 17, A, No. 6. Stockholm. 20 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY.

But there is sufficient material of the nearly allied S. buchholzi, and this may serve to reveal some facts of anatomy, still unknown in this genus. The pallial organs (text-fig. 1) show the same arrangement of kidney and ureter as described by Pilsbry (1919,3 p. 191, fig. 68) in Yaricosteh bequaerliana; thus the nephridium occupies a transverse position at the bottom of the lung cavity and sends a short right lobe along the intestine forwards. Its front thus describes Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 a well-marked concavity occupied by the ureter, which is closed in its whole extent; it debouches, at the side of the anus, in the roof of the pneumostome, a small furrow carrying off the excretion. In shape and position this nephridium is similar to that of the Ferussaciidoe (cf. below), which shares the transverse extension with

FIG. 1.—Streplostek buchholzi. Fio. 2.—Edenlulina martenji. Pallial organs. Pallial organs. the heterurethrous type (Succineidse), where, however, there is no right lobe along the intestine and the front margin of the kidney is convex instead of concave. Along the mantle edge there runs a large glandular zone to the left of the anus, but there is no anal gland on the right side. It is of interest to compare this form of nephridium with that of Edentulina martensi. Here (text-fig. 2), in correlation with an 3 Review of the Land Mollusks of the Belgian Congo. Bull. Atner. Mus. N.H., vol. 40.- ODHNER : AFRICAN LAND SHELLS. 21

attenuating of the lung backward, the kidney has undergone a displacement so that its length is parallel to the long axis of the lung. But still it keeps the same relation to the heart along its short left side as is also characteristic of Streptostele, and a similar protraction of the kidney along the ureter beside the intestine. The latter, as in Streptostele, too, does not pass directly backwards, as e.g. in 4

Achatinida; and Ferussaciidce (cf. Watson, 1928, pi. 4, fig. 9, pi. 5, Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 fig. 7), but bends and runs parallel to the base of the lung, only separated from it by a small liver lobe, a condition met with in other genera of Streptaxida). In the radula of Streptostele buchhohi, which measures 3-5 mm. in length and 0-5 mm. in breadth, are to be numbered only twenty- six rows of teeth with 10.1.10 as maximum. The median tooth

a. albumen gland. d. vas defercns. p. penis, opened. b. bursa copulatrix. e. appendix of penis. r.p. retractor penis. c. spermatocyst. g. gonad. u. uterus.

FIG. 3.—Slreptoslde buchhohi. FIG. 4.—Streptosleh buchhohi. A half-row of the radula. x 75. Genital organs. and the four innermost laterals are narrowly spine-shaped, the fifth tooth suddenly increases in size as regards both base and cusp, and the five outermost marginals again decrease rapidly in breadth and length. Their shape is shown in text-fig. 3. Compared with Streptostele, Edentulina martensi has no median tooth, and the laterals (about twenty-seven on each side), are all subequal and of the elongate spine-like type ; only the six or seven outermost ones are markedly smaller, more crowded and slender. As to the genital organs, Slrejrtostele (text-fig. 4) is remarkable

4 The Affinities of Cecilioides and Ferussacia, illustrating'adaptive evolution. I J. Conchoh, vol. 18, p. 217. 22 PROCEEDINGS OF THE JIALACOLOOICAL SOCIETY. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 FIG. 5.—Slreplosteh buchholzi. FIG. 6.—Edentulina martemi. Armature of the penis. X 450. Armature of the penis. X 75.

a. albumen gland. d. vas deferens. p. penis. b. bursa copulatrix. g. gonad. r.p. retractor penis. c. spermatocyst. m. ampulla. u. uterus.

FIG. 7.—Edentulina marlensi. Genital organs. in exhibiting an appendix on the penis similar to that of Varicoslele (cf. Pilsbry, 1919, p. 191, fig. 686), but stouter. The upper end of the penis is muscular and carries a band-like retractor passing to the columellar muscle ; all the remaining part is a hollow tube with the walls, interiorly, densely papillate (text-fig. 5). Each papilla bears in its tip a claw-like hollow hook covered with a thin epithelial membrane. In the distal portion of the genital organs the bursa copulatrix is remarkable for its long stalk: the bursa ODHNER : AFRICAN LAND SHELLS. 23 proper is lodged at the side of the albumen gland. The hermaphrodite duct is short and carries a comparatively elongate, coiled spermatocyst. The gonad is a rather compact aggregation of small rounded follicles, and is situated at the end of the fourth whorl, embedded in the liver, which alone fills the apical whorls of the shell.- In Edenlulina martensi the genital organs offer some differences

to Slreptostele of systematic importance. The penis is slender, Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 cylindric and, in its distal part (in a short or long space) furnished with a sheath concealing also a loop of the vas deferens (text-fig. 7). Interiorly the penis is armed with dense chitinous hooks projecting directly from the wall of the penis (text-fig. 6), and much stronger than in Streptosldc ; they are arranged in quincunxial order. The bursa copulatrix has a short stalk. In the upper parts, there appears a small spermatocyst close to the albumen gland. The hermaphrodite duct describes a conglomerate ampulla, and the gonad consists of a few separate tufts of follicles.

GONOSPIRA PALANGA Ferussac. In order to solve the question about the systematic position of the Canarian " Gonospira " dealbala, "Webb & Berthelot (which has been treated in another publication 5), I tried to get some material of the typical Gonospira species from Mauritius for comparison. Since no material seemed to be obtainable in European museums, I wrote to Mr. d'Emmerez de Charmoy in Mauritius asking him to procure me, if possible, some well-preserved specimens of this genus endemic there. Mr. d'Emmerez de Charmoy passed over my letter to Mr. R. Viader, M.B.E., keeper of the Conchological Section of the Museum of the Mauritius Institute, and Mr. Yiader most kindly sent me some good specimens of G. palanga. I offer here my cordial thanks to these two gentlemen for this valuable material, which has enabled me to examine the chief anatomical characters of the conchologically well-known but anatomically still unknown G. palanga, type of the genus Gonospira Swainson. These facts may suitably be published in this connection as a contribution to the little' known organization of the family Streptaxidas. In G. palanga the mantle has an intensively brick-red maculation ; along the right margin of the lung there runs, besides, a violet zone. The pallial organs (text-fig. 8) are somewhat aberrant from those of the species just described. The kidney occupies a position about intermediate between them, and reminds one of the typical sigmurethrous form, since it is elongated in the long axis and even projects a little beyond the pericardium in front. The chief part of the nephridial chamber is rectangular and comparatively compressed (its breadth somewhat less than length), and does not project any

5 Beitrage zur Malakozoologie der Kanarischen Inseln . . . Arlivfor Zooltxji, vol. 23, A, Xo. 14, Stockholm, 1931. 24 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY.

a, Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021

TIG. 8.—Gonospira palanga. Pallial organs.

FIG. 9.—Gonospira palanga. Genital organs. a. albumen gland. b. bursa copulatrix. d. vas deferens. g. gonad. in. ampulla. o- egg. p. penis. FIG. 10.—Gonospira pala/iga. r.p. retractor penis. Armature of tho penis, x 75. u. uterus. lobe along the intestine forwards. The ureter has a normal S-formed curvature. Behind the kidney the intestine describes a compressed loop, before it proceeds to the anus. Nephrostome and anus are as in the preceding species. There is a brown-pigmented anal gland to the right of-the anus and, to the left of it, a glandular band along the mantle edge. ODHNER : AFRICAN LAND SHELLS.

In the structure of the male genital organs Gonospira palanga (text-fig. 9) approaches more to Edentulina than to Streplostele, inasmuch as the penis is a cylindrical tube without appendix. It is slender and elongate, and armed internally with'small conical hooks rather scattered and projecting directly from the wall of the penis (text-fig. 10). The retractor of the penis is narrow and band-

like, but strong ; it joins the columellar muscle. The bursa copulatrix Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 has a very long stalk, which is swollen at the base. In one specimen the uterus contained one egg of 3 mm. diameter. The upper parts of the genital organs exhibit a short albumen gland but no spermatocyst, and a contorted ampulla of the hermaphrodite duct. The gonad consists of a few scattered follicular tufts. Quite as in the preceding genera, the genital organs in Gonospira palanga lie to the right of and free from the right tentacular retractor. The radula (text-fig. 11), lodged in the foremost end of the very large pharyngeal cylinder, measures 11 mm. in length and 3 mm. in breadth, and shows a close agreement with that of Edentulina, inasmuch as all teeth are spine-shaped. They are arranged in seventy rows, with 36.1.36 teeth as a maximum. The small median tooth is of the same shape as the next laterals, and could be reckoned to them as well. The laterals increase in size up to the twelfth tooth and then slowly decrease again; the outermost marginals are more crowded than the remaining teeth.

Via. 11.—Gonospira palanga. A half-row of the radula. x 75. As to the external habitus of the animal it may be noted that the foot is covered with rounded square cutaneous warts arranged in longitudinal series so as to present the appearance of an ill-defined marginal furrow. There is no caudal pore in the blunt end of the foot, and the sole is undivided.

HOIIORUS CONNOLLYI n. sp. (Plate 2, figs. 3-6.) Shell ovate-conic with pointed apex, corneous yellow with longitudinal brown flames and stripes of varying breadth, here and there confluent. Whorls eight, convex, comparatively depressed, margined, at least the ultimate one, below the suture and constricted below the margination'; last whorl about three-fifths of the shell's height, rather ventricdse below. Sculpture : apical whorl smooth ; 26 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. in the fourth or fifth whorl revolving striae appear, which cut the irregular lines of growth into small undulations with the convex side towards the front. No umbilicus. Aperture broadly ovate, scarcely two-fifths of the height, bluish-white inside ; outer lip thin, sharp, slightly convex, forming a very acute angle with the parietal wall; this latter covered with a very thin enamel layer. Golumella with

an S-formed curvature, and with a very conspicuous notch below. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 Maximum dimensions: height 30, breadth 15, height of aperture 12, breadth of aperture 7, height of last whorl 19-5 mm. About a dozen specimens of this peculiarly short and broad new species of Ilomorus were collected in 1915 by Mr. A. J. Allen Turner at Kagamagoes, N. Kanarogo, British East Africa, and sent to the State Museum, Stockholm. Major M. Connolly has kindly confirmed that it is a new species belonging to Ilomorus, and it is a pleasure to me to name it in honour of that eminent.expert in African land shells, whose publications have contributed so much to our knowledge of these mollusca.

gggg FIQ. 12.—Ilomorus connollyi. Teeth from the radula. x 240. The present shell has a very characteristic shape distinguishing it from all other species of Ilomorus and more recalling certain species of the genus Pseudoglessula; it shares, however, the smooth apex of Ilomorus, as well as the same micro-sculpture of the whorls (Plate 2, fig. 5), with a few species of that genus, e.g. //. erlangeri Kobelt.6 That it belongs to Ilomorus is proved also by the dentition of the radula, which was extracted from a shell bearing an epiphragma within its mouth. The radula contains about one hundred and thirty rows of teeth, numbering each up to 50.1.50 (text-fig. 12). The median tooth has a simple cusp. The fourteen lateral teeth have a pointed cusp and a single ectocone ; the fifteenth tooth is the first marginal and has a broad cusp and an endocone added. In the outermost marginals the ectocone and the endocone are level with the median cusp. In the same specimen the jaw was a simply curved and finely transversely striated piece without teeth or prominent lamellae. As to the epiphragm, it is formed by a thin calcareous sheath

6 The same sculpture is also observable in H. olivaceus Pollonera (cf. Pilsbry, 1919, pi. 17, fig. 7n). r

ODTINER : AFRICAN LAND SHELLS. 27

with a fine pore near the upper angle (Plate 2, fig. 6); from this pore a short tube projects into the pneumostome of the animal. Inside the outermost epiphragm there were two others composed of two or three thin lamella; each. SUBULIXA ANGUSTIOR Dohm. Some specimens of this species from Camerun were dissected in order to compare them to S. oclona, the anatomy of which was Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 carefully described by Wiegmann (1898)7 and Baker (1927).8 The pallial organs / (text-fig. 13) are of the same type, the / kidney being sigmurethrous and extend- *— ing along the lung about twice the length of the heart, and the long ureter being reflected and closed in all its length. It opens into the pneumostome close to the anus in the normal way. The anus lies close to the right of the pneumostome and within the same pocket. There is no special anal gland in the wall of the latter. To the left of the anus, however, the general broad glandular zone is extending along the inner margin of the mantle edge, as in the Streptaxidse. In the radula of Subidina anguslior (text-fig. 14) there are about a hundred rows: of teeth amounting to 30.1.30, in each, all tricuspid, the outer marginal teeth having, like the laterals, their Fla# mesocone longer than the outer cusps; the ectocone is sometimes double. The genital organs (text-fig. 15) are similar to those of S. octona, well described by Baker (1927). We find (text-fig. 16) a very small penis having the shape of a simple tube somewhat attenuating proximally. Near its base a muscle (m) inserts without forming a sheath (cf. Baker), and this muscle, farther back, joins the pharyngeal retractors and the retractor oculi. The vas deferens crosses beneath this penial muscle and runs close along the penis wall loosely attached to it by means of a thin membrane. At about two-thirds of the penis-length the vas deferens describes a sharp reflexion and debouches into the penial tube causing a projecting duplicature of its wall. The course of the penial tube is continued beyond this

7 Land-Mollusken (Stylommatophoren): Zootomischer Theil, Abh. Senckenberg. Ges., vol. 24. • The Mollusca collected by the University of Michigan-Williamson Expedition in Venezuela. Occas. Papers J/us. Zool. Michigan, No. 182. 28 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021

Fio. 14.—Subulina angustior. Teeth from the radula. x 450.

V

FIG. 15.—Subulina angustior. Distal genital organs.

FIG. 16.—Subulina angustior. Penis. c. columellar muscle. /. flagellum. in. basal penial muscle. p. penis. ph. pharynx. ' \ retractor penis. FIG. 17.—Subulina angustior. t. tentacular retractor, Retractor system. r. vas deferens. ODHXEE : AFRICAN LAXT> SHELLS. 29

-joint in the shape of a narrow flagollutn, about half the length, of tie penis. At its tip the broader retractor is attached, which inserts r,v its other end at the columellar muscle. Text-tig. 17 gives a scheme of the retractor system. The existence of a basal penial muscle and its combinations as well as in the connection of the vas deferens along the penial tube might be interpreted as features of survival of an uncompleted stage of development.

In the external habitus of this species is to bo observed a peculiar Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 -iJge on each side of the tail, formed by a row of about twelve cutaneous warts, which are compressed, elevated and elongated in -he length of the foot. A similar ridge has been observed by d'Ailly •.;i Ganomidos (= CaUistope-pla), where it is rather conspicuous ; i: also occurs in the next species. Along the foremost half of the foot there is a marginal furrow. No caudal pore is present. NEOGLESSO'LA (?) L.^VTGATA Pfeifler. Two specimens of this species identified by Major Connolly and preserved in alcohol were kindly placed at my disposal for anatomical examination by Mr. Hugh Watson, and one of them was dissected. External!}7 this species proves to be akin to SubiiMna, inasmuch ;.s it shows the same pedal crests, though shorter and consisting of fewer (only four largo posterior and three to four small anterior) —arts. The tail, otherwise, tapers to an acute point with no caudal pore ; a marginal furrow is distinct only in the front part of the :cot (cf. text-fig. 18),

1 .lie. 18.—A 'eoglesnula (?) kevigata. Foot. o -crests (tentacles withdrawn). X 12. In the pallial organs (text-fig. 19) also the same type is manifested

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, '-Lac

FIG. 19. Fia. 20. FIG. 21. Neoglessula (?) Icevigata. PIE. 19.—Pallia] organs : a, anus ; c, heart; i, intestine; n, kidney ; p, pneumostome; u, ureter. Fio. 20,—Distal genital organs : r.p., retractor penis ; r.t., retractor tentaculi. i'lQ. 21.—Plagellum sac of penis, onened ;, r, retractor penis ; v, vas deferens. ( X 48) much stronger developed in relation to the bursa copulatrix than in that genus. Further, it has a different shape and structure (cf. text-fig. 21). It is narrow distally, but widens proximally into a claviform saccular fiagellum produced into a small coccum, from the top of which the long filiform retractor issues to the diaphragm. In the median part of the ilagelltun sac the vas deferens debouches. This comes from below following the penis upward, and, at the under end of the dilated sac, attaches itself for a short space to the outer wall of the latter. At the insertion of the sac, the vas deferens opens by means of a longitudinal fissure. The inner walls of the flagelluin sac are strengthened by muscular cords which extend from the opening of the vas deferens in the longitudinal direction of the sac, and are arranged concentrically round a small ovate thickening at the upper end of the fissure mentioned : this pad, however, does not project even as the smallest gland. The cords issue symmetrically on both sides of the opening of the vas deferens. ODHNER : AFRICAN LAXD SHELLS, 31

On the wall opposite the latter, the cords meet together in a naked line, which, on account of the swollen ends of the cords and their alternating approach in the coecum, here gets a winding appearance. This form of penis evidently has arisen from a simpler tube (something like that of Pseudopeas) by means of a one-sided dilatation combined with a tension of its wall caused, as it seems, by the retractor muscle. It thus represents a more differentiated stage Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 than that of Opeas, but is not so advanced as Siibidina in its lack of the long flagellum of the latter genus. The vagina is long and slender, and bears a small bursa copulatrix with a rather short and thick stalk. In the uterus were no eggs or embryos. Pilsbry examined the radula of Ar. Icevigala and gives (Manual Conch., 1909, pi. 15, fig. 9) all teeth tricuspid and the marginals with comparatively narrow projecting mesocone, though this is apparently broader in the outer marginals, as Connolly figures (1928,9 p. 542, text-fig. 8), a character also found in N. curia (Connolly, Moll. Abyssinia, p. 172, text-fig. 2).10 The jaw of N. lavigata is plaited (cf. Pilsbry, 1909, pi. 15, fig. 10); a specimen examined by me showed the plicae convergent in the middle, as in Ferussaciidse. Whether the present species is a true member of the genus Neoglessula Pilsbry, 1909, is doubtful. Originally established on Achalina parilura Gould as type, on account of the spirally sculptured embryonic whorls, this genus was extended by Connolly in 1928 ll to comprise also Achalina Iwvigata Pfeiffer, left by Pilsbry in Glessula, because this species was found to share the essential characters of Neoglessula. We must await anatomical particulars from the type species, before the generic position of the present form can be settled.

PSEUDOPEAS EGEXS d'Ailly. (Plate 2, figs. 7-9.) Described as Opeas this species was placed by Pilsbry in his Manual (1906, vol. 18, p. 115) in Pseudopeas on account of the fine spiral striation on the apical whorls pointed out by d'Ailly. This sculpture is too fine to appear in the figures, given here since the species has not been previously illustrated. Figs. 7 and 8 show two typical shells from Kitta, fig. 9 an aberrant form from Bonge (a locality not mentioned in d'Ailly's work); the latter specimen was, however, designated as Opeas egens by d'Ailly. It measures not less than 7 • 3 mm. and has seven whorls, whereas d'Ailly gives, in his diagnosis, 5-6 mm. and six whorls as characteristic of the typical form. Otherwise, even this is somewhat variable in shape * The non-marine Mollusca of Sierra Leone. Ann. Mag. X.U. (10), vol. 1. 10 On a coll. of Land and Freshwater Mollusca from Southern Abyssinia. Proc. Zool. Soc. (1928). 11 Moll. Abyssinia, loc. cit., p. 171. 32 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. and convexity of the whorls. Connolly has reported this species from Sierra Leone. The foot of P. egens has a •well-marked marginal furrow, but no caudal pore and no tail crest. The radula (text-fig. 22) has about 20-22.1.20-22 teeth in the

largest rows. Median and lateral teeth are tricuspid ; from about Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 the eleventh tooth there are added several ectocones, so that the marginal teeth get a pectinate edge, the mesocone and endocone being, however, somewhat larger than the remaining denticles.

FIG. 22.—Pseudopeas egtns. FIG. 23.—Pseudopeas egeiw. Teeth from the radula. x 450. Jaw. x 100.

FIG. 25.—Pseudopeas egens. Distal genital FIG. 24.—Pseudopeas egens. organs, b, bursa copulatrix; r.p., Pallial organs. retractor penis. The jaw (text-fig. 23) is 0-35 mm. in length and has its surface sculptured with distant and winding furrows rendering to its upper half a vermiculate appearance. In the pallial organs (text-fig. 24) we find a sigmuretlirous kidney, which, however, doe3 not differ much from that of Edenlulina described above ; the heart is only a little shorter than the length of the kidney, and this is extended to the right at the base of the lung. ODHNER : AFRICAN LAND SHELLS. 33

The rectum continues straight backwards and the intestine sends an open loop towards the base of the nephridium. A posterior vena pulmonalis is distinct following the recurrent part of the ureter. This is closed, and opens normally. In the mantle edge only a glandular zone to the left of the anus, but no anal gland proper, is observable. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 In the male organs of Psewlopeas egens (text-fig. 25) the penis is very much reduced in size (only 0-5 mm. in length), but it is not at all vestigial. The small male organ is dilated proximally, and in this part is contained a small muscular fold depending from the wall at the side of the sperm-canal. There is no flagellum; the retractor inserts directly on the top of this dilated portion. The vas deferens runs closely at the outer wall of the penis, as in Subulina beneath a thin sheath, and opens from beneath in the dilated sac. Further, there is a very short bursa copulatrix, and the uterus contains from one to three eggs in a series.

CURVELLA COSTELLATA n. sp. (Plate 2, figs. 10, 11.) Shell comparatively large, turreted, perforated, with produced spire and subacute apex and slightly convex or nearly straight sides, thin, straw-yellow, half-opaque with irregular hyaline spiral streaks, especially in the last whorl. Whorls 7, very convex, suture deep, simple ; last whorl about three-fifths of the shell's height. Sculpture : apical whorl smooth, subsequent whorls with faint close vertical riblets (about twenty-five complete ones visible on the last half- whorl), somewhat irregular in position and strength, separated by equally broad shallow furrows, and curved forwards. There is no spiral sculpture, but a fine hyaline lineation most conspicuous in the last whorl. Aperture subovate, shorter than half the shell's height, peristome sharp, outer lip produced and curving forwards in its upper half, receding below. No parietal callus. Columella slightly convex and oblique, passing without marked sinus into the peristome; columellar margin narrowly reflected, enclosing the fine umbilical perforation. Dimensions : height 7-2, breadth 3-1; height of aperture 3 mm.; whorls 6J ; and height 9, breadth 3-4, height of aperture 3-G mm.; whorls 7. Only two specimens of this characteristic species were collected in Camerun (without definite locality) by P. Dusen in 1892 (d'Ailly's collection). The smaller one is chosen as type, the larger one, besides being more elongate, is aberrant in having two small tooth-like knobs on the parietal wall, evidently occasional, and two similar ones on the columella. This new species is remarkable for its pronounced costellation and the fineumbilica l perforation, characters also significant of other species of Curvella, above all 0. ovala Putzeys from the Congo Basin, but this species has a larger last whorl and aperture. In its slender shell, more convex whorls and shorter VOL. xx.—MAKcn, 1932. 3 34 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. aperture, the present new species also differs from the similarly sculptured species of Ourvella described by Connolly in 1928 from Sierra Leone, most of which arc distinctly costellate ; only one of them, however, (C. langrannana) shares the umbilical perforation of the present species. This is, on the other hand, rather similar to an Opens, were it not for the curving costae, which allot it to

CurveUa. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 Both specimens contained dried animals showing in their oviducts about ten small spherical eggs (about 1 mm. in diameter) placed in a single series. One of the specimens was examined for the jaw and radula. The jaw is a narrow yellow ribbon (0-4 mm. in length) of a fibrous structure and with a slightly fimbriated edge. In the radula (text- fig. 26), which is 1 mm. long and 0-5 mm. broad, are contained about 125 rows with about 40.1.40 teeth. The small median tooth (its cusp only 0*008 mm. in length) has a small denticle on each side of the narrow central cusp. The lateral teeth have a strong mesocone,1 and an ectocone and an endocone which are much smaller than the mesocone ; in tooth 11 the denticles are subequal, and in teeth 13-15 their number is five, owing to the bipartition of the ectocone ; the remaining marginals (up to twenty-five in number) are all finely pectinate.

13

18

Fro. 26.—CurveUa costdtata. Tcetli from the radula. x 720.

This structure of the radula is strikingly different from that of Opeas ; in 0. gracile, Ilutton, from the West Indies, I found only 2G.1.2G teeth in the transverse rows. The median and lateral teeth are tricuspid; in tooth 17 the ectocone becomes split up, but even in the outermost teeth the mesocone and the endocone are some- what larger than the outer denticles (as in Pseudopeas egens). In a typical CurveUa, on the contrary, my object of examination was C. langi Pilsbry, 1919 (loc. cit., pi. 20, figs. 3, 4), the radula in all essentials agrees with that described above. Here the median tooth is indistinctly tricuspid, the laterals distinctly so; in tooth 10 the ectocone becomes bipartite and all denticles become subequal; the edge is thus serrate in all the marginals (up to tooth 40). ODHXEK : AFRICAN LAND SHELLS. ,»

PsECTJOGLESSULA EETIFERA VOn Martens. The pallial organs are, similar to those of Suhulma angustior, thus presenting a sigmurethrous kidney, extended more than twice the length of the heart, and a marginal mantle gland but no anal gland. The intestine runs and debouches quite as in Subulina, and there is no posterior lung vein and no marginal branch of the anterior pulmonary vessel. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021

Fin, 27.—Pseudogless'ttla retifera. Jaw. x 24. The jaw (V9 mm. in length) (text-fig. 27) is almost smooth, its surface showing a weak radiation caused by alternating convex and concave stripes, as well as a minute undulation of striae parallel to the convex margin.

r.tx.

I 28.—Pseudoglessida relifera. FIG. 29.—Pseuiioglesmila retifera. Distal 'Teeth from the radula. X 285. genital organs and retractors, p, penis, opened; r.b., retractor bulbi; r.p., retractor penis ; r.i.i., retractor of inferior tentacle ; t, tentacle ; o, genital opening. The teeth of the radula (text-fig. 28) amount to 71.1.71 in the -ongest rows. The comparatively broad median tooth has a single >road cusp with no side denticles. The laterals have an eotocone 36 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY. at the base of the large median cusp. In the outer laterals the cusp becomes shorter and blunt, and directed obliquely inwards. On about tooth 24 or 25 a small endocone appears, and the outermost marginals are irregularly tricuspid or pectinate. The penis (text-fig. 29) has a proximal dilatation and a short

epiphallus in which the retractor is inserted ; this unites with the Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 retractor bulbi. In the dilatation of the penis the walls are plicate inwardly, and there is a depending cylindric body, similar to that in Pseitdopeas egens. The bursa copulatrix has a thick and short stalk. Pilsbry (1919) has described and figured the foot of P. ualikalensis ; in retifera there is also a well-defined marginal furrow and a caudal pore, but no lateral crests. LIMICOLARIA KOBELTI, d'Ailly, 1896. (Plate 2, figs. 14-18.) This form was collected in the same locality in Camerun, Bonge, as Limicolaria rubicunda, and is, indeed, very similar to that species in colour, shape and sculpture. The chief character of L. kobelli, according to d'Ailly, is the open umbilicus limited by an obsolete keel, where as in L. rubicunda the umbilicus is somewhat contracted by a constriction of the columella just below the body wall and a correlative expansion of the reflected columellar lip. But in some specimens of L. rubicunda represented in the collection the same shape of the umbilicus as in L. kobelti may be observed. As to the sculpture this is, in L. kobelli, decidedly weaker than in L. rubicunda, but of the same kind and appearing as a rule most distinctly beneath the suture. One of the most typical features in L. kobelli is the small canal in the aperture, close to the base of the columella, but in L. rubicunda a similar canal is indicated, too. On account of the fact that these differences are more gradual than essential, I think it necessary to include L. kobelli within the limits of L. rubicunda, though it may be held apart as a distinct variety. Since it was never figured, I give five photographs showing the chief characteristics as well as variation in shape.

COXNOLLYA CAMERUNENSIS n. gen., n. sp. (Plate 2, figs. 12, 13.) Shell comparatively large, imperforate, cylindric-conic, with produced spire, obtuse apex and slightly convex sides, smooth, polished, half-hyaline and shining, covered with a thin straw- yellow cuticle. Whorls 5J, slightly convex, suture oblique, shallow, margined ; last whorl equalling somewhat more than two-thirds of the shell height, almost cylindric in its median part, being flattened below its convex upper third and swollen at the side opposite the columella. Sculpture only very weak lines of growth curving forwards. Aperture equal to half the length of the shell, narrowly subovate, produced above ; peristome simple, thin, strongly sinuous below the straight and perpendicular, white, obliquely truncate columella; outer lip curving forward in the middle, parietal wall with a thin and broad enamel covering and separated from the ODIIXEll : AFRICAN LAXT> STTELLS, 37 columella by a deep basal excavation. Dimensions: height 8-4, breadth 8-4, height of aperture 4-2 mm., (type) : and height 7-8, breadth 2-8, height of aperture 3.9 mm. Two specimens are at hand, both from Bonge, Camcrun (P. Dusen, 1591). Each has one large egg in the uterus, somewhat flattened spherical and measuring 1-5 mm. in diameter, Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021

FIG. 30.—Connollya camerunensis. Jaw. x SO. The jaw (text-fig. 30) is a yellowish band about 0*8 mm. in length ,'j^d. 0-13 mm. in breadth; its surface is ribbed transversely with nattened comparatively broad costae. the ends of which project at 'cL-d cutting edge. The radula (text-fig. 31) contains about 100 rows of teeth with about 15 +9.1.9 + 15 in each. All teeth are tricuspid. The marginal teeth, from tooth 10 or 11, become much abbreviated but keep the same breadth as' the inner ones, so that their median cusp grows extremely short and broad, appearing lastly as a narrow ledge setween the tips of the, small ectocone and endocone ; in the outer- most marginals these elements are still further reduced to become t .lite invisible.

FIG. 31.—Connollya ca-merurtensis. Teeth from the radula. X 800. This shape of the radula and that of the jaw, together with the •:cliche-logical characters of this new species, above all the straight ccxumella, distinguish it from all known genera of Achatinacea and requires the establishment of a new genus with the species just described as type. With this new genus I should like to connect Air. M. Connolly's name in appreciation of his valuable work on Aliican mollusca, and therefore I propose for it the name Connollya. 38 PROCEEDINGS OF THE MALACOLOGICAL SOCIETY.

By means of boiling one of the present specimens in soda, ammonia and pure water alternately and, now and then, leaving it in alcohol, I succeeded in softening the animal completely and getting it to project so much within the aperture that it could be extracted by means of a needle. It appeared to be in rather good state of

preservation (having apparently, before its drying, been preserved Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 in alcohol), enabling me to study its anatomy and state some particulars of systematic importance. The foot, though somewhat contracted, showed clearly the marginal furrows, a deeper upper one and a finer lower one, which are characteristic of the Ferussaciidae but only exceptional in Achatinidae (e.g. Pseudoglessula). Narrow and elongate dermal warts, which diverge from a fine median furrow on the back of the foot to the marginal grooves, make the resemblance to the- foot of a Ferussacia complete. A very characteristic feature is the presence of an anal pocket with a large anal gland in Connollya, which seems to place this genus in the relationship of Ferussacia and Ccecilioides, since this gland is generally lacking in the Achatinidae (in Neoglessula lavigala an anal portion of the marginal gland is present, v. supra). Watson (1928, p. 222) rightly considers the presence of this gland as " a strong evidence in favour of the mutual affinities of these two genera ". In Connollya the gland is relatively large, thus recalling the embryonic stage of Ferussacia (cf. Watson, text-fig. 1,2), causing the rectum and the ureter to bend to the left from the lung margin. There is no glandular zone of the same extension along the mantle edge, which makes Connollya differ from Neoglessula lavigala. The pallial organs were not well retained after the softening of the animal, partly due to the presence of the large egg in the uterus. The kidney lies transversely across the base of the lung, but it does not seem to project along the intestine as in Ferussacia; unfortunately, its habitus could not be definitely stated, though it might be of the heterurethrous type. Another characteristic that Connollya shares with Ferussacia is the habitus of the liver, inasmuch as this, from its right side, protrudes a narrow lobe along the right side of the intestine. In Ferussacia this lobe follows the intestine rather far in front of the lung base ; in Connollya this extension is much shorter, but wholly distinct, but in Neoglessula Iwvigala the corresponding right lobe does not by far reach the lung, and the latter condition is found also in Subulina, Pseudopeas and Pseudoglessula. Finally, the animal extracted presented the distal genital organs, by dissection, so unexpectedly well, that I was able to corroborate the conclusion of the probable relation to the Ferussaciidae. The penis (text-fig. 32) is, in its distal end, a thin canal; proximally it widens to a muscular cylinder surrounded by an external sheath loosely connected by muscle cords to the internal cylinder, the fore- ODHNKR : AFKICAN LAND SHELLS. 39

most end of which projects like a small glans. Thus the structure of the penis recalls that of Caecilioides described by Wachtler in his beautiful work on C. acicula (1929, p. 445, fig. 70).12 This structure of the penis, further, is different from the type prevailing in the Achatinidae and Stenogyridae; it comes nearest to that of Caecilioides (cf. also Watson, loc. cit., pi. 5, figs. 4, 5), though it is still simpler. Further there is a short vagina with a short-stalked Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021 bursa copulatrix.

FIG. 32.—Connollya camerunensis. Distal genital organs, b, bursa copulatrix ; p, penis; u, uterus. Thus the examination of the animal, so far as it could be made, renders it likely that Connollya belongs to the Ferussaciidae and answers to the following diagnosis. Shell cylindric conical, with thin, simple peristome and truncate, perpendicular, straight columella. Kidney heterurethroid (?). Penis dilated to a muscular cylinder proximally, without any appendages. Anal gland well developed. Jaw ribbon-like curved, with narrow transverse flattened ribs. Radula with the teeth tricuspid, the marginals abbreviate, very broad, and with extremely low mesocones. Conchologically, the new genus Connollya differs clearly enough from similar subulinoid shells, such as Nothapalus and Neoglessida, not only in its smooth apex, but above all in its straight columella ; in the genera mentioned the columella is concave. Moreover, Neoglessida, according to Pilsbry, is viviparous, whereas Connollya seems to be oviparous. Further, the jaw and radula are considerably different from those of Neoglessula (v. supra). As to Nothapalus, Mr. Connolly sent me specimens of N. paucispira for comparison of its radula, which is figured in text-figure 33 and represents the general subulinid type. This is the case, also, with the jaw, which is finely striate. Thus there are sufficient grounds for holding the

12 Anatomic und Biologie dcr Cccilioides acicula. Z. llorph. Oehol., vol. 13 •(1029). 40 PROCEEDINGS OF THE JIALACOLOGICAL SOCIETY. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021

FIG. 33.—Xolhapalus paucispira. Teeth from the radula. x 240. new species apart from Neoglessula and Nolfiapalus as the type of a distinct genus. According to the above statements, Connollya is interesting inasmuch as it seems to realize in nephridium, anal gland and radula a primary stage of organization corresponding somewhat to the embryonal one of Ferussacia. The heterurethroid kidney and anal pocket and gland are characters of no usual occurrence in the Pulmonata, and for this sake it is rather interesting that these same formations, combined, moreover, with a jaw of the divergently plicate type1, are met with in the genus Aillya Odhner (1927),13also t'ndemic in West Africa ; the typical species, described by me as camerunensis, but shown by Connolly (1929)14 to be identical with catena Spencc 1925,15 and a second species, totipunctala Connolly, 1929, are found in Camerun. The genus Aillya, however, on account of its radula, belongs to the family Bulimulidae ; but the agreements pointed out make it probable that not only Achatinidae, but also Bulimulidae have a common source with the Fcrussaciidae,- and that these three families of Pulmonata may have radiated from a common centre of evolution.

EXPLANATION OF PLATE 2. FIG. 1.—Pedipes dohrni d'Ailly. Type, x 5. 2.—Streptostele pusilla d'Ailly. Type. X 6. 3.—Homorus connoJlyi n.sp. Type. Nat. size. 4.—Homorus connollyi. Cotype. Nat. size. 5.—Microsculpture in the shell surface of //. connollyi. x 7. 6.—Epiphragma of II. connollyi, from inside, x G. 7, 8.—Pseudopeas egens d'Ailly. Cotypes. x 6. 9.—Pseudopeas egens, elongate form with 7 whorls. X o. 10.—Cunella costellata n.sp. Cotype. X 3-5. 11.—Curvella cosidlata. Type, x 3-5. 12.—Connollya camerunensis n.sp. Type. X 3-5. 13.—Connollya camerunensis. Cotype. x 3-5. 14-18.—Limicolaria kobelti d'Ailly. Cotypes. Nat. size. •

13 Aillya camerunensis n.gen., n.sp., An African Bulimuloid Snail. Artiv for Zoologi, vol. 19 A, No. 20. 14 Notes on African Non-Marino Mollusca, etc. Ann. Mag. N.II. (10), vol. 3, p. 174. 15 On a Coll. of Moll, from the Camcroons. J. Conchol., vol. 17, p. 250, PKOC. MALAC. SOC. LOXD. VOL. XX, PL. 2. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021

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AFPJCAS LAXD SHELLS. Downloaded from https://academic.oup.com/mollus/article/20/1/19/1034089 by guest on 27 September 2021