STALK-EYED CRUSTACEA 263 



I. Bathyplax typhlus. 



Batliyplax lypJdus . . A. Milne Edwards. 



The carapace flat transversely, but very curved from 

 before backwards ; its surface is covered with very fine 

 granulations, slightly elevated, and so has a rough appear- 

 ance. The regions are slightly marked, especially in 

 front ; behind these exist very distinct branchio-cardiac 

 grooves, and two grooves surmount the branchial regions 

 outwardly. The latero-anterior borders are bowed, thick, 

 and armed with two spines, one hepatic one terminal. 

 The ocular peduncles have the form of two small 

 projecting warts ; they are fastened at their base in the 

 orbits, which allows them no mobility. The basal articu- 

 lation of the external antennae is large and pressed 

 between the orbital border and the subfrontal prolonga- 

 tion ; its flagellum, inserted in the angle of the orbit, is 

 long. The basal articulation of the internal antennae is 

 remarkably large. The buccal cavity is very open and 

 very notched in front. The third joint of the external 

 maxillipedes is large ; the fourth is rounded at its antero- 

 external angle. 



The first pair of legs subequal and of moderate length ; 

 the arm does not exceed the carapace, it carries below a 

 spine, and above a sort of transverse rack arranged in such 

 a manner so as to rub against the granulations of the 

 pterygostomian region. The forearm carries on the right 

 side a spine and on the left side a tubercle or a weak 

 spine. The left pincer is the shortest, and has on the 

 inside a triangular dilatation which is a prolongation of 

 its superior border. The external face of the hand is 

 depressed, and the inferior border very fine and very 

 bowed. The fingers are compressed, pointed, and in 



