REPORT ON THE CRUSTACEA MACRURA. 297 



pair, which goes to form the outer plates of the tail-fau ; this is biramose and supported 

 by strong longitudinal ridges, the outer marginal one is very strong and terminates in a 

 sharp tooth, short of the terminal extremity, in connection with a well-defined diaeresis. 



Obsei-vation. — The specimen supposed to be the type of Palsemon carinatus, from 

 which M. Olivier drew his description, was found in the Museum of the Jardin des Plantes 

 without any indication of the locality where it was obtained, but if it be the same as 

 that author described, it was brought from New Holland by Peron, but that which 

 Milne-Edwards gives in his Histoire naturelle des Crustaces came from Rio Janeiro, where 

 Dana also procured some specimens and says that it is common. 



Sicyonia lancifer (Olivier) (PL XLIII. fig. 4). 



Palsemon lancifer, Olivier, Eneyclop., t. vi. p. 664, pi. cecxvii. fig. 2. 



Sicyonia lancifer, de Haan, Siebold's Fauna Japonica, p. 194. 



Hippolyte crisfata, de Haan, loc. cit., Tab. xlv. fig. 10. 



Sicyonia lanci/er, Milne-Edwards, Ann. d. Sei. Nat., ser. 1, t. xix. p. 341, note, 1830; Hist. Nat. 



Crust., vol. ii. p. 410. 

 Sicyonia crLtata, Stimpson, Prodromus descrip. Crust, mac. ; Proc Acad. Xat. Sci. Philad., p. 112, 



1860. 



The rostrum is obliquely elevated ; armed with a single tooth on the lower surface 

 at the extremity ; crested on the dorsal median line of the carapace, and armed with 

 four small teeth on the rostrum, four larger ones posteriorly, and one large sharp 

 tooth on the hepatic region. 



The pleon is carinated and but slightly compressed laterally. The carina on the first 

 somite is produced anteriorly to a small tooth, and on the last to a large one directed 

 posteriorly ; the carina on each somite is double-ridged longitudinally, and cleft pos- 

 teriorly to receive that of the next succeeding somite. The last three somites have 

 the coxal plates posteriorly produced to sharp teeth. The telson is tapering and 

 terminally flanked by a sharp tooth on either side, and with a fringe of strong hairs. 



Length (female), 50 mm. (2 in.). 



Habitat.— Station 188, September 10, 1874; lat. 9° 59' S., long. 139° 42' E. ; 

 Arafura Sea, south of Papua ; depth, 28 fathoms ; bottom, green mud. One specimen ; 

 female. 



This specimen appears to me to coincide with MUne-Ed wards' description of Sicyonia 

 lancifer (Olivier). De Haan's figure of Sicyonia {Hippolyte) cristata also corresponds with 

 the Challenger specimen, and the descriptions of the tw r o agree with that given by Olivier 

 under the name of Palsemon lancifer. There is but one specimen in the collection, 

 and that a female. It is less compressed laterally, both anteriorly and posteriorly, 

 than Sicyonia carinata ; the teeth are more numerous on the median dorsal ridge, and 



(ZOOL. CHALL. EXP. — PART LIL — 1886.) Fff 38 



