Mr, C. Spence Bate on a new Genus of Macrura. 15 



with all the group, and present a cliaracter in the presence 

 of the styloeerite that disting-uishes them from those 

 that belong to tlie Trichobranchiata, and makes me much 

 regret that the previously desiccated condition precludes a 

 satisfactory examination of the branchial structure. In most 

 of the recent forms allied to Eryonidje the inner margin 

 of tlie first joint of the ])eduncle of the anntenna is 

 laterally produced into a broad and thin plate which is pro- 

 jected upward in the median line in consequence of its 

 meeting a similar projecting plate belonging to the oppo- 

 site side. In a few species it is reduced in importance 

 to little more than a big tooth ; but it is absent generally 

 from all other genera of the Trichobranchiata. On the outer 

 side there is no styloeerite such as we find conspicuous in 

 all the Phyllobranchiate Macrura and exists in a modified 

 form in the Dendrobranchiata. In the species now under 

 consideration it is prominent, well defined, and of considerable 

 tenuity, and therefore in this character approaches that of the 

 Phyllobranchiata. 



The second pair of antennae have the flagellum broken ; 

 but from its proportions it may be assumed to have been about 

 the lengtli of the carapace or perhaps a little longer ; the 

 scaphocerite is leaf-like and hairy, and has the margin on the 

 outer side rigid and produced to the rudiment of a tooth, while 

 the inner side is fringed with fine ciliated hairs, the whole 

 structure bearing a membranous character of extreme tenuity. 



The mandibles ((/) are powerful organs, smooth along the 

 psalisiform or cutting margin, with the molar protuberance 

 short and robust, and on the outer surface there exists a 

 three-jointed, synaphipod or appendage, which differs from the 

 typical forms of the recent Eryonidge in which there are only 

 two joints, but corresponds with most other families of the 

 normal Trichobranchiata. 



The first pair of siagonopoda (e) or maxillae bear a resem- 

 blance to those of Wil/emcesia, but differ in the possession 

 of a small joint on the outer side of the chief branch. 



The second pair (/) resemble more nearly those of the 

 family Astacida3 and differ chiefly in not having the masti- 

 gobranchial plates posteriorly produced, but rounded off" 

 short. 



The third pair (^) are in a more advanced condition than I 

 have found in any of the typical Macrura and have the primary 

 branch six-jointed and support a well-developed multiarticu- 

 late basecphysis. 



The first pair of gnathopoda (h) are well developed and 

 pediform, having the basis very long and furnished with a 



