CEUSTACEA, 563 



cannot be given ; but it is somewhat smaller than adult P. tridacnm. 

 The chelipede of the second pair measures about 7 lines (15 millim.). 



Two specimens, of which one is an adult female with ova, were 

 obtained at the Seychelles (12 fms.), where they inhabited " clamp 

 shells " (bivalves ?). 



They are distinguished from all the species with which I am 

 acquainted, except P. vmdeng, Kingsley; by the extremely short 

 rostrum, which is not laterally compressed, and from all by the form 

 of the chelipedes of the second pair. Prom the species of Gorallio- 

 caris, Stm. (CEdipus, Dana), they are distinguished, among other 

 characters, by the form of the dactyli of the ambulatory legs. 



In P. unidens, Kingsley, from Florida*, not only is the form of 

 the chelipedes different, but also the antennal scale is shorter, reach- 

 ing only to the end of the last joint of the peduncle. 



6. Coralliocaris gramiuea (Dana). 



Four specimens, of which two are adult females with ova, were 

 obtained at the Seychelles, 4-12 fms. (No. 194). Specimens from 

 the same locality were presented, to the Museum by Dr. E. P. 

 Wright. 



These specimens agree with the description of Dana in all par- 

 ticulars except that no trace remains of the characteristic markings 

 of the carapace, the coloration in spirit being yellowish ; and the 

 margins of the rostrum above the eyes are slightly convexly ar- 

 cuated ; the tooth on the inferior margin of the rostrum, or one of 

 the teeth of the superior margin, is occasionally absent. 



Dana's specimens were from the Fijis. Dr. Stimpson records 

 this species from Hong Kong. 



Coralliocaris nudirostris (HeUer), from the Eed Sea, may possibly 

 be identical with this species ; but in the figure the dactyli of the 

 chelipedes are of very different form (c/. Heller in Sitz. Wien. 

 Akad. xliv. (1) p. 279, pi. iii. fig. 25, 1862).. 



7. Penseus canaliculatus, Olivier. 



A small specimen, I think a male, was obtained at Poivre Island, 

 on the beach (No. 198). 



Since reference was made to this species in my memoir on the 

 genus, in 1878 1, specimens have been added to the collection from 

 Eichmond Eiver, N. S. Wales {A. P. Goodwin) ; there is also in the 

 Museum collection a small example, in bad condition, from Swan 

 Eiver (Bring). x 



Penceus hrevirostris, KingsleyJ, is~ very nearly allied to, and may 

 be identical with, this species, but it has two teeth on the inferior 



* Proo. Acad. Nat. Sci. Philad. p. 422, pi. xiv. fig. 9 (1879). 



t Proc. Zool. Soc. p. 298 (1878). 



1 Proo. Acad. Hat, Sci. Philad. p. 98 (1878), 



2o2 



