^^AsinAnaf/ia^/inrthe rostral hornsaretvvo; they are long and 

 divergent, but at their base there is a supra-orbital spine which 

 in Anamathia is wanting, and the orbital region offers special 

 characters. The orbit is more complete than in the Crustacea of 

 the neighbouring groups, and the eye is retractile hiding in a 

 groove left between the carapace and a flattened projection 

 behind the orbit. The basal joint of the external antennae is un- 

 armed, and juts out a little so as to form a sort of orbital platform; 

 it is flattened below; the movable portion of the antennae at its 

 insertion is partially concealed under the rostrum, of which, being 

 short, it does not reach the apex. The carapace is piriform, and 

 its salient parts generally form flattened protuberances, which are 

 somewhat analogous to the fungiform productions of the body in 

 the genus Eurynonic- The external maxillipeds are remarkable 

 for the rounded form of the antero-external angle of the fourth 

 joint, the opposite angle being truncate to receive the articulation 

 of the palp." The feet are long and strong, the fingers of the 

 chela are sharp. The first ambulatory foot reaches beyond the 

 others; its joints are cylindrical, and end in a finger slightly 

 curved and apically acute. The pleon has seven segments, and is 

 W'ithout spines ; in the male the seventh segment is narrow and 

 attenuate at the end ; in the female it is very broad. The 

 branchise and the appendages are of the normal oxyrrh3nchal 

 type. 



The authors of this definition assign to the genus only Scyra- 

 mafhia carpcntcri (Norman) and Scyramaihia occidcntalis (Faxon). 

 They do not agree with Faxon in placing these species in 

 Anamathia, because the type of the latter, A. rissoaua (Roux), 'is 

 well characterized by its small orbits^ with upper margin entire, 

 and without pre-orbital and post-orbital spines. They remark that 

 the American species of Aitaniathia, A- hystrix (Stimpson), A. 

 crassa, A. M.-Edw. (including A- agassizi, S. L Smith). A. 

 tanner i. Smith, and A. mod est a (Stimpson). all have orbital spines,, 

 and might thus be distinguished from A- rissoana, forming a 

 gradual transition to Scyramaihia. But at all events, they con- 

 clude, the latter is distinguished from the former ' l)y the external 

 widening which the basal joint of the second antenna? forms 

 under the orbit, by the absence of spines upon that joint, and, 

 lastly, by the transformation of certain dorsal spines of Anamathia 

 into low tubercles, ordinarily truncate at the extremity.' Scyra 

 umhonata, Stimpson, which A- Milne-Edv/ards had transferred 

 to Scyramathia, is indirectly withdrawn from it by the joint 

 authors. After ahuding to the suspicion entertained by Sars that 

 Stinipson's species might even prove to be identical with Scyra- 

 maihia carpcntcri, they say, " it is easy to determine the profound 

 differences which separate these two crustaceans, not only in 



* The authors use the t-xpressioii " tigdle mobi.e " to designate the last tliree 

 joints of the third maxillipeds, anJ also the movab'e pait oC tli^ second antennae, 

 including stem joints and flagellum. 



