Crustacea, Decapoda: Dromiacea

THE METAMORPHOSIS OF A SPECIES OF HOMOLA (CRUSTACEA, DECAPODA:

DROMIACEA) 1

ANTHONY L. RICE Institute of Marine Science, University of Miami

ABSTRACT Large decapod zoeas and megalopas taken in the Straits of Florida and held in the laboratory through one moult are described and identified as the species of Homola designated "barbata" by Rathbun (1937). However several differences are noted between these zoe as and homolid zoeas described from the Mediterranean, where H. barbata is the only species of the genus known to occur. It is suggested that H. barbata, as it is currently considered, may consist of more than one subspecies, or even species, with distinct larvae.

INTRODUCTION The dromiacean section of the Brachyura, containing the superfamilies Dromiidea and Homolidea, consists of a number of rather primitive crabs which are generally held to be close to the stock from which the rest of the Brachyura arose (Glaessner, 1960). Although the group is therefore of considerable phylogenetic importance the larvae are relatively poorly known. Even in those species of which larvae have been described. only one or two stages have usually been dealt with, and in only one case (Dromia vulgaris Milne-Edwards) has anything approaching the complete larval development been described (see Pike & Williamson, 1960). Larvae attributed to the genus Homola have been described by Boas (1880), Cano (1893), Thiele (1905), Aikawa (1937) and Pike & Wil- liamson (1960), but none of these larvae have been identified with certainty, since in no case have they been linked with a definitely identifiable stage. Living homolid zoeas and megalopas taken in the Straits of Florida and held through one moult in the laboratory have been identified tentatively as Homola barbata (Fabricius) and are described here.

MATERIAL AND METHODS Six terminal zoeas: Straits of Florida off Miami, 25° 45' N, 79° 52' W to 25° 35' N, 79° 52' W; estimated depth 133 m; Isaacs-Kidd mid-water trawl fished from 1930 hrs. to 2130 hrs. RjV GERDA cruise 6338, station G-195, September 9, 1963. Three megalopas: Straits of Florida off Miami, 25° 35' N, 79° 52' W to 25° 33.5' N, 79° 52' W; estimated depth 333 m; Isaacs-Kidd mid-

IContribution No. 539 from The Marine Laboratory, Institute of Marine Science, Uni- versity of Miami. This investi~ation was supported in part by Public Health Service Research Grant GM ] 1244-01 from the National Institute of Health. Research Grants G-16298 and G-20355 from the National Science Foundation, and a Harkness Fellowship of the Commonwealth Fund. 222 Bulletin of Marine Science of the Gulf and Caribbean [14(2) water trawl fished from 2208 hrs. to 2305 hrs. R/V GERDAcruise 6338, station G-196, September 9, 1963. All of these larvae were held at 20° C and about 36 ppt salinity, and fed on Artemia nauplii and small pieces of shrimp. The water was changed every two days. Two of the zoeas died without moulting, one died in the process of moulting to the megalopa and three moulted successfully to the megalopa after 4-1'0 days in the laboratory but died before reaching the first crab stage. One of the megalopas died without starting to moult, one died after moulting incompletely and one moulted successfully to the first crab on the 27th day after capture and died five days later. Exuviae and dead animals were preserved in 70 per cent alcohol with 10 per cent glycerine added. They were stained with chlorazol black, dis- sected in glycerine and examined under a binocular microscope. Measurements were made with the aid of an ocular micrometer. The total length (TL) was measured from the tip of the rostrum to the posterior median margin of the telson, excluding the telson processes, and the carapace length (CL) was measured from the tip of the rostrum to the posterior median margin of the carapace. Drawings were made with the aid of a camera lucida. In many of the illustrations the secondary setules are omitted for clarity, and even where they are indicated their representation is diagrammatic since no attempt at quantitative accuracy was made in the case of these structures.

DESCRIPTION Terminal zoea (Fig. 1) .-CL 5.2-5.8 mm; TL 10.4-11.4 mm. In addi- tion to the acute forwardly directed rostrum the carapace has three blunt dorsal projections in the mid-line and well developed paired supra-orbital and branchiostegial spines anteriorly. On each side there is a pointed anterolateral spine, a shorter pointed posterolateral spine, a blunt dorsolateral projection, and a prominent downwardly directed spine at the posteroventral corner. Other prominent features of the carapace include a small bulge on either side of the anterodorsal projection, a larger median hemispherical bulge behind this projection, and a system of low ridges connecting the major carapace spines. Abdominal somites 2-5 each have a mediodorsal spine and paired dorsolateral spines, all of which decrease in size posteriorly. The first somite has only a blunt dorsal projection and somite 6 has a pair of long dorsolateral spines but no dorsal spine. Ventrolaterally on abdominal somites 1-6 there are posteriorly directed projections which become more prominent posteriorly. The telson is wider than long (L/W ratio 0.64-0.70) with concave posterior and lateral margins and acute posterolateral corners. There 1964] Rice: Metamorphosis of Homola 223

FIGURE 1. Homola barbata: Terminal zoea. a, Dorsal view.-b, Lateral view. --c, Posterior dorsal view of carapace. Bar scale represents 5 mm. 224 Bulletin of Marine Science of the Gulf and Caribbean [14(2) are 37-46 plumose processes articulated to the posterior margin, every 4th to 6th such process being rather larger than the rest. There is a pair of large dorsal spines on the telson, close to the lateral margin. Abdominal somites 2-5 each carry a pair of biramous, non-setose pleopods (Fig. 2f and g) which are considerably better developed in late terminal zoeas than in earlier examples of the same stage. The sixth somite carries well developed uropods, the external rami each with about 50 plumose setae and the inner rami each with 4'0-45 plumose setae. The eyestalks consist of a narrow proximal portion and a swollen terminal portion on the anterior margin of which there is a prominent spine immediately proximal to the corneal region. The antennular peduncle (Fig. 2a) is completely segmented and has a rudimentary statocyst in the proximal portion. The three-segmented inner flagellum is unarmed and the outer flagellum consists of nine or ten segments of which all but the proximal two carry a row of aesthetes (about 50-60 in all). The antennal endopod (Fig. 2b) consists of 14-16 segments and carries a single terminal seta. The sub-ovate scale carries 34-39 long plumose setae. There is a single unarmed spine on the basipodite at the base of the endopod. The mandibles (Fig. 2c) each have an unsegmented palp which may carry a non-plumose terminal seta. The endopod of the maxillule (Fig. 2d) is two-segmented, bearing a total of six long plumose setae. The endites are armed with many fairly stout setae. The scaphognathite of the maxilla (Fig. 2e) has a large, bilobed posterior projection and carries about 110 plumose marginal setae. The endopod is unsegmented and carries 10-12 long plumose setae. The basal and coxal endites are both bilobed and are armed with many marginal and sub-marginal setae. The exopods of the maxillipeds (Fig. 3a, band c) each have a con- striction at about the mid-point and carry 21-26 nata tory setae. The endopods of all three maxillipeds consist of five segments, though the septa between the second, third and fourth segments in the third maxilliped are not very clear. The medial margin of the basipodite bears 20-24 setae in the first maxilliped, four in the second and two in the third. The segmentation of the developing pereiopods (Fig. 3d, e and f) is visible beneath the zoeal cuticle and the first pair are already cheliform. The first, second, and third legs each carry a small exopod, but this structure is apparently missing in the fourth and fifth pairs. The zoeas are generally orange-red in color, with at least part of this coloration being deep in the thorax and in the eyestalks. However, the surface of carapace and abdomen have numerous red chromatophores 1964] Rice: Metamorphosis of Homola 225

b c f g

a d e

FIGURE. 2. Homola barbara: Terminal zoea. a, Antennule.-b, Antenna.-c, Mandible.-d, Maxillule.-e, Maxilla.-f-g, Pleopods of second and fifth abdominal somites, respectively. Bar scales represent 1 mm. 226 Bullet;n of Ma,;ne Sdence of the Gulf and Car;bbean [14(2)

FIGURE 3. Homola barba/a: Terminal zoea. a, b, c, First, second, and third maxillipeds, respectively.-d, e, f, First, second, and third pereiopods, rcspe<:t- ively. Bar scale represents 1 mm. which also extend into the proximal parts of the appendages. Megalopa (Fig. 4).-CL 7.25-7.50 mm; TL 12.0-12.75 mm. The downwardly directed rostrum projects slightly farther than the paired frontal spines. The carapace has three low blunt projections in the mid-line and several other paired knobs and bulges. There is a well-marked groove separating the gastric and hepatic regions. The whole surface of the carapace carries short setae, those in the gastric region each arising from a small tubercle. These surface tubercles are enlarged in certain localized areas of the anterolateral region of the carapace. The abdominal tergites are well rounded from before backwards and 1964] Rice: Metamorphosis of Homola 227

FIGURE 4. Homola barba/a: Megalopa. a, Dorsal view (the bases of the legs on the right side are shown in their true positions but those on the left are somewhat displaced for clarity) .-b, Lateral view of anterior part of carapace, with antennules, antennae and eyes removed. Bar scale represents 5 mm. also laterally. The abdominal armature seen in the terminal zoea has almost completely disappeared, but there are minute remnants of the mediodorsal processes on somites 1-5 and of the dorsollaterals on the sixth somite. The pleopods (Fig. 7d) are now setose and are largest anteriorly. The number of plumose setae on the exopods decreases from 52-53 on those of the second somite to 37-40 on those of the fifth somite. 228 Bulletin of Marine Science of the Gulf and Caribbean [14(2) The endopods of the pleopods carry 9-12 minute hooks. The inner rami of the uropods (Fig. 5) carry 43-49 marginal setae and the outer rami carry 57-63 setae. The telson is very slightly longer than wide and is somewhat variable in shape (Fig. 5). There is a row of 43-46 plumose setae extending along the posterior margin and about one third of the lateral margins. There are many simple setae on the dorsal surface. The difference in width between the corneal region of the eye and that immediately proximal to it is less than in the terminal zoea and the spines on the anterior margin are no longer present. The antennular peduncle (Fig. 6a) is now completely segmented and a granular statolith is visible in the statocyst. The outer flagellum consists of 12-16 segments, with a row of aesthetes on the second to ninth, tenth or eleventh segment, the total number of aesthetes not being deter- mined. The basipodite of the antenna (Fig. 6b) carries a small scale. There are two large peduncular segments distal to the basipodite and a flagellum consisting of 31-36 segments. The mandibular palps (Fig. 6c) are three segmented and are armed with many setae. The endopod of the maxillule (Fig. 6d) is longer than in the terminal zoea and carries more setae but otherwise this appendage has not changed very greatly. The scaphognathite of the maxilla (Fig. 6e) has increased in size reIa-

FIGURE 5. Homola barbata: Megalopa. a, Tail fan, dorsal view.-h, c. Outlines of two other telsons showing variation in shape. Bar scales represent 1 mm. 1964] Rice: Metamorphosis of Homola 229

b a c d e

FIGURE 6. Homola barbata: Megalopa. a, Antennule.-b, Antenna.-c, Mandible.-d, Maxil1ule.-e, Maxilla. Bar scales represent 1 mm. tive to the cndites and now has about 15'0 marginal setae and a single longer seta at the posterior corner. There are several non-marginal setae on the anterior lobe of the scaphognathite. The endopod has lost the setae on the medial margin, except for one in some cases, and now has a number of short setae on the proximal part of the lateral margin. The endites are more deeply cleft than in the terminal zoea and they carry more setae, 23'0 Bulletin of Marine Science of the Gulf and Caribbean [14(2) the terminal ones being spinous while the non-terminal ones have longer setules.

FIGURE 7. Homola barbata: Megalopa. a, b, c, First, second and third maxillipeds, respectively.-d, Pleopod of fifth abdominal somite. Bar scale represents 1 mm. 1964] Rice: Metamorphosis of Homola 231 The endopod of the first maxilliped (Fig. 7a) is a two segmented keeled structure armed with many setae and with a strong spine distally. The exopod is articulated at about its mid-point and is further segmented distally where it carries about 18 marginal setae and three or four medial ones. There is a foliaceous epipodite and a large basal endite armed with many setae. The endopods of the second and third maxillipeds (Fig. 7b and c) each have five segments and the exopods are essentially similar to that of the first maxilliped except that in the third maxilliped the exopod carries about 27 marginal setae and eight medial ones. The epipodites of both these appendages are long and narrow and carry many flexible setae marginally. The chelae (Fig. 8a and b) are equal and similar. The hands are laterally flattened and the propodus is bulbous dorsally. The merus and ischium

I FIGURE8. Homola barbata: Megalopa. a, Mediodorsal view of left cheliped.- h. Left chela, medial view.-c. d, e, Propodus and dactyl of second, third and fourth legs, respectively.-j. Fifth leg. Bar scale represents 1 mm. 232 Bulletin of Marine Science of the Gulf and Caribbean [14(2) are prismatic in shape with edges dorsally, ventrally and laterally. There is a row of eight spines on the dorsal edge of the merus and there may be two additional small blunt projections. The ventral and lateral edges each carry six projections. The ischium has a large dorsal spine, one lateral projection and four ventral ones. The armature of the dactyl, propodus, carpus and merus of legs two to five (Fig. 8c and f) is basically similar in having a dorsal and ventral row of strong setae and five or six other longitudinal rows of smaller setae. The ventral row on the dactyl of legs two, three, and four consists of 11-13 particularly strong spines and on leg five, of four strong spines. The fifth leg also has a terminal group of long setae on the dactyl and two large spines on the ventral margin of the propodus. The coxae of legs one to four have a small posterior distal projection and the merus of the second leg has three blunt projections on the ventral margin.

FIGURE 9. Homola barbata: First crab. Bar scale represents 5 mm. 1964] Rice: Metamorphosis of Homola 233 First crab (Fig. 9) .-CL 9.0 mm. Portions of the anatomy of the first crab are illustrated in Figure 10. The mouth parts are basically very similar to those of the megalopa and are not illustrated. The specimen possesses all the diagnostic features of Homola barbata (Fabricius) including a carapace which is considerably longer than broad, a bidentate rostrum, a median gastric spine situated posteriorly on the

c-1

abhij I g

FIGURE 10. Homola barbata: First crab (laboratory-moulted specimen). a, Antennule.-b, Antenna.-c, d, e, Left cheliped, dorsal, ventral and medial views.-j. Ventral aspect of body.-g, Telson, ventral view.-h, i, j, Pleopods of first. second and fifth abdominal somites. Bar scales represent 1 mm. 234 Bulletin of Marine Science of the Gulf and Caribbean [14(2) wide part of the mesogastric region, a lobe on the second segment of the antennal peduncle, 11-15 strong spines on the ventral margins of the dactyls of legs two to four and a narrow, curved dactyl on the fifth leg. These characters distinguish H. barbata from H. vigil, which is the only other species of the genus recorded from the western North Atlantic. In gross anatomy the specimen also agrees very closely with an adult female and a juvenile (probably a first crab stage), collected off Martha's Vineyard, Massachusetts, (No. 7301 in the collection of the U.S. National Museum) and with a juvenile stage (also probably a first crab) collected off Miami, about l.5 miles SSE of the sea buoy (No. 32.863 in the collection of the Institute of Marine Science of the University of Miami). There are, however, some differences, notably in the number of spines on the dorsal edge of the merus of the second to fourth legs (Table 1). Gonopores are not visible in the first crab stage (Fig. 10f), but the two museum specimens examined possess a pair of large grooved appendages on the first abdominal somite (Fig. 11a) and are therefore probably males. These specimens also possess a pair of biramous, non-setose pleopods on each of the succeeding four somites (Fig. lib) whereas the adult males carry appendages only on the first two abdominal somites.

L-~

FIGURE ] 1. Homola barbata: First crab (no. 32.863 in the collection of the Institute of Marine Science). a, Appendages of first abdominal somite.-b, Appendages of second abdominal somite. Bar scale represents 1 mm. 1964] Rice: Metamorphosis of Homola 235 The laboratory reared first crab, on the other hand, has a pair of very small appendages on the first abdominal somite (Fig. 1Oh) and well developed paired biramous pleopods on abdominal somites 2-5 (Fig. 10i and j), and is probably a female. If these deductions as to the sex of the first crabs examined are correct it is apparent that the differences in leg spination noted above are not attributable simply to sexual dimorphism.

DISCUSSION Cano (1893) described a late zoea of a homolid from Naples and Thiele (1905) described one from Messina. Pike & Williamson (1960) point out that Cano probably made an error in illustrating setose pleopods in his dorsal view of the abdomen, particularly since he did not show these structures in the lateral view. Thiele's zoea shows a greater development of the antennule and antenna, and a narrower telson than Cano's specimen. Pike & Williamson suggest that Cano's larva is the penultimate zoea (stage 4), and Thiele's the ultimate zoea (stage 5), of Homola barbata. While the terminal zoea described above is generally very similar to those of Cano and Thiele, there are a number of differences. The anterior medial dorsal carapace spine in the Mediterranean larvae is situated rather farther forward than in the Caribbean zoeae described here, and the form of the posterior border of the carapace in the illustrations of both Cano and Thiele, with a pair of strong spines close to the mid-line, is also very different from mine. Both Can a and Thiele illustrate two pairs of dorsal spines on the telson whereas only one pair is present in the Caribbean larvae. Cano figures, and mentions specifically, a median telson spine considerably smaller than the rest of the telson processes; Thiele's figure shows no such median spine and neither was one seen in the pres- ently described specimens. The presence of setose pleopods in Cano's dorsal view and the absence of pleopods in his lateral view has already been mentioned. Homola barbata is the only known representative of the genus in the Mediterranean, and Pike & Williamson therefore attributed the stage 1 and stage 2 zoeas which they described, and also the late zoeas of Cano and Thiele, to this species with reasonable certainty. In the Caribbean region only two species, H. barbata and H. vigil, are known to occur and the larvae described above are definitely attributable to barbata rather than to vigil (see above). It is possible that some of the differences noted between these larvae and the illustrations by Cano and Thiele are due to errors of the authors concerned, but it seems highly improbable that all of the discrepancies are attributable to the same cause, particularly since the Mediterranean larvae agree so closely while differing from the Caribbean ones. If the differences are real there is the possibility that 236 Bulletin of Marine Science of the Gulf and Caribbean [14(2) H. barbata, as it is currently considered, may include more than one sub-species, or even species, with distinct larvae. Boas (1880) examined one homolid zoea (CL 7.0 mm) from the South African region west of Cape Town and one (CL 3.0 mm) from south of Madagascar. His illustration of the carapace of the smalJer specimen is very similar to mine, while the telson, which has no dorsal spines and only 32 processes, is similar in shape to Cano's. Three species of Homola, including H. barbata, have been recorded from South Africa (Barnard, 1950). Pike & Williamson felt that the absence of dorsal telson spines in Boas's larvae from this region indicated that they belong to a species other than barbara. However, since the larvae of the Caribbean and Mediterranean H. "barbata" apparently differ in this same character, Boas's larvae may represent a third larval form in the complex. Bouvier (1940) gives a figure of 0.4 mm for the mean diameter of the eggs of H. barbata and a similar value was obtained from measurements of eggs on the H. barbata from Massachusetts which was examined. How- ever, these eggs contained early embryos and it is likely that at hatching the eggs would be almost I mm in diameter so that the first zoea could be expected to be about 2 mm in total length. This agrees well with Pike & Williamson's measurement of 1.9 mm for their first zoea. If their ];uvae and the terminal zoea described here indeed represent the same species and are the end points of a series of five zoeal stages, it would be necessary for the larvae to increase in length by rather more than half at each moult.

TABLE 1 NUMBER OF SPINES ON THE MERUS OF LEGS Two, THREE AND FOUR OF THE FIRST CRAB STAGES OF Homola barbata OBTAINED IN THE LABORATORY, AND OF THREE MUSEUM SPECIMENS EXAMINED Completely moulted Incompletely moulted Juvenile from Miami First Crab (CL 9.0 mm) First Crab (CL not del.) No. 32.863 (CL 9.2 mm)

Left Right Left Right Left Right Leg 2 8 7 5 5 5 6 Leg 3 8 8 5 5 4 4 Leg 4 5 5 3 3 3 3

------Juvenile from Mass. Adult

Left Right Left Right Leg 2 5 6 5 missing Leg 3 4 4 4 4 Leg 4 3 missing 3 3 ---~ 1964] Rice: Metamorphosis of Homola 237 Though this figure is certainly not unprecedented, it is rather high. Irrespective of the number of zoeal stages an interesting feature of the development of this species is that the carapace length of the first crab stage is apparently almost half that of the mature adult. SUMMARY HomoIid zoeas and megalopas taken in the Straits of Florida were held at 20°C in the laboratory and fed A rtemia nauplii and small pieces of shrimp. Some of the zoe as moulted to the megalopa after 4-10 days in the laboratory, and one of the animals captured as a megalopa moulted successfully to the first crab stage 27 days after capture. None of the animals passed through more than one moult in the laboratory. The terminal zoea, megalopa and first crab are described and illustrated and tentatively identified as Homola barbata (Fabricius). The Caribbean zoeas are compared with published descriptions of homolid larvae from the Mediterranean, where H. barbata is the only species of the genus known to occur, and certain differences are noted, mainly in the shape of the carapace and in the number of dorsal spines on the telson. It is suggested that H. barbata, as it is currently considered, might include more than one subspecies, or even species, with distinct larvae. The spination of the legs of the first crabs obtained in the laboratory and also of several museum specimens of H. barbata are compared. The complete first crab reared in the laboratory differs considerably in this character from all of the other specimens examined and these differences are apparently not attributable simply to sexual dimorphism. ACKNOWLEDGMENTS My thanks are due to Mr. Won Tack Yang and Mr. Sheldon Dobkin for providing the living material and to Dr. R. B. Manning for the loan of specimens from the collection of the U.S. National Museum. I also wish to thank Dr. A. J. Provenzano for his encouragement and for his critical reading of the manuscript. The living material was collected during a cruise of R/V GERDA supported by grant G-20355 from The National Science Foundation, and the study was carried out during tenure of a Harkness Fellowship of the Commonwealth Fund. I am indebted to both of these agencies for their support. SUMARIO METAMORFOSISDE UNA ESPECIE DE Homola (CRUSTACEA, DECAPODA: DROMIACEA) Zoeas y megalopas de hom61idos cogidas en el Estrecho de la Florida fueron mantenidas en ellaboratorio a 20°C y alimentadas can nauplius de Artemia y pequefias porciones de camar6n. Algunas de las zoeas mudaron a megalopa despues de 4-10 dfas en el laboratorio y uno de los animaks 238 Bulletin of Marine Science of the Gulf and Caribbean [14(2) capturado en estado de megalopa mud6 felizmente al estado de primer cangrejo 27 dras despues de su captura. Ninguno de los animates pas6 mas de una muda en el laboratorio. Se describen e i1ustran la ultima zoea, la megalopa y el primer cangrejo y tentativamente se identifican como Homola barbata (Fabricius). Se comparan las zoeas del Caribe con descripciones public ad as de larvas de hom61idos del Mediterraneo, donde H. barbata es la unica especie del genera que se sabe esta presente y se notan ciertas diferencias, principal- mente en la forma del carapacho y en el numero de espinas dorsales del telson. Se sugiere que H. barbata, como se considera corrientemente, pueda inclurr mas de una subespecie, 0 aun especies, con larvas distintas. Se comparan las espinas de las patas del primer cangrejo obtenido en el laboratorio y tambien las de varios ejemplares de museD de H. barbata. EI primer cangrejo completo criado en el laboratorio difiere considerable- mente en este caracter de todos los demas ejemplares examinados y estas diferencias aparentemente no son atribufbles simplemente a dimorfismo sexual.

LITERA TURE CITED AIKAWA, H. 1937. Further notes on brachyuran larvae. Rec. oceanogr. Wks. Jap., 9: 87-162. BARNARD, K. H. 1950. Descriptive catalogue of South African decapod Crustacea. Ann. S. Afr. Mus., 38: 1-837. BOAS, J. E. V. 1880. Studier over Decapodernes Slaegtskabsforhold. K. danske vidensk. Selsk., Ser. 6, Nat. og Math., Afd. 1 (2): 25-210. BOUVIER, E. L. 1940. Decapodes marcheurs. Faune de France, 37. Paul Lechevalier, Paris, 399 pp., 14 pis. CANO, G. 1893. Svillupo dei Dromidei. Atti Accad. Sd. fis. mat. Napoli, (2) 6 (2): 1-23. GLAESSNER, M. F. 1960. The fossil decapod Crustacea of New Zealand and the evolution of the order Decapoda. Palaeont. Bull. N.Z., 31: 1-79. PIKE. R. B. AND D. I. WILLIAMSON 1960. Larvae of decapod Crustacea of the families Dromiidae and Homo- Iidae from the Bay of Naples. Pubbl. Staz. zool. Napoli, 31 (3): 553-563. RATHBUN, MARY JANE 1937. The oxystomatous and allied crabs of America. Bull. U.S. nat. Mus., 166: 1-278. THIELE, J. ]905. Ober einige stielaugige Krebse von Messina. Zool. Jb., Suppl. 8 (Festschr. F. Mobius ): 443-474. WILLIAMSON, H. C. ]915. Decapoden, I. Teil (Larven). Nord. Plankt., 18 (6): 315-588.