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.