CRUSTACEA 



By EDWAPiD J. MIEES, Junior Assistant, ZooloCxICAl Department, British Museum. 



The greater number of the Crustacea here figured have been described by Mr. Adam White. The plates having 

 been printed off many years since, and the stones destroyed, it has not been possible to alter their lettering, and bring 

 it into correspondence with the nomenclature adopted in the text ; but whenever I have adopted for any species a 

 different generic or specific name from that used by Mr. Wliite, and printed on the plate, a reference has been made 

 to the latter in the synonyma of the species. 



Decapoda Brachyura. 



Sub-tribe Maioidea, Dana. 

 Wilke's U. S. Explor. Exped. XIII., Crtist. I., p. 66 (1852). 



Genus Xenocarcinus, White. 



App. Juke's Voy. H. M. S. Fhj (1847) ; Proc. Zool. Soc, p. 



119 (1847). 



(Huenioides, Milne-Edwards, Ann. Soc. Entom. de France, 

 (ser. 4) V. p. 144 (1865). 



This genus is referred by Dana to his Family Periceradce, 

 of which the distinctive characters are, the non-retractile 

 eyes, and moderate legs, but it will probably be necessary 

 in future systematic arrangements to unite this Family 

 and the Euryjwdidce, Dana, or to modify the characters, for 

 the eyes are often slightly retractile in the Periceradce, and 

 the genus Oregonia, placed by Dana in the Eurypodidce, has 

 shorter legs than Eurypodius, approaching in this respect 

 the genera of Periceradm. 



The genus Huenioides, Milne-Edwards, is certainly 

 synonjTBOus with Xenocarcinus. It agrees with it in the 

 narrow elongate form of the carapace and rostrum, in the 

 eyes, antennte, and outer maxillipeds : also in having the 

 beak covered with close short hair, and in the tarsi being 

 finely denticulated below. X. tuberculatus, White, may 

 be at once distinguished from X. (Huenioides) conicus, 

 ililne-Edwards, /. c. p. 144, by its more oblong form, 

 shorter, stouter rostrum, and strongly tuberculated carapace. 



Xenocarcinus tuberculatus. Tcth. 2, Jij. 1, a-e. 



Xenocarcinus tuberculatus, A. White, Append. Jukes' 

 Voy. Fly, p. 336 (1847) ; Proc. Zool. Soc, p. 119 (1847) ; 

 List Crust. Brit. Mus., p. 123 (1847) ; A. & M. N. H. {ser. 

 2) I.,_p. 221 (1848). 



Hab. Cumberland Group. Type. B.M. 



Tab. 2, fig. 1. Animal twice nat. size. \a Side view 

 of carapace and rostrum, nat. size. Ih. Under surface, 

 twice nat. size. Ic. Outer mxped. Id. Outer antenna. 

 If. Tarsus, all more enlarged. 



In the British Museum there are five specimens (three 

 male and two female) of a species of Xenocarcinus, -which 

 I believe is undescribed, and propose to call Xenocarcinus 

 deprcssus, in allusion to its flattened carapace. 



Xenocarcinus depressus, sp. n. 



Carapace to base of rostrum, when viewed from above, 

 regularly oval in outline ; the uppersurface flattened. 

 There are several small granules behind and between the 

 eyes at the base of the rostrum, and irregular indistinct 

 granulated elevations in the middle line, and on either side 

 of the carapace, occupying nearly the same positions as the 

 conical tubercles of X. tuberculatus. Eostrum subcylin- 

 drical, densely pubescent, terminating in two spines and 

 deeply excavated between them. Eyes, antennae and outer 

 maxillipeds as in X. tuhercxdatus. First pair of legs want- 

 ing in the females, in the males they are shorter than tlie 



