STALK-EYED CRUSTACEA 29 



6. Trachymaia. 



Tracliymaia . . A. Milne Edwards. 



The carapace is subpyriform, short, wide, and curved 

 posteriorly. The interorbital space of moderate width. 

 The floor of the orbit has a spine at its edge. The 

 rostrum is small, composed of two diverging spines 

 separated by a deep notch. The eye, of which the 

 cornea is a little compressed in front and behind, is 

 folded in a fossa at the base of the postorbital spine. 

 The orbits are very open above and below. The basal 

 joint of the external antennae is very narrow, and does 

 not enclose the orbit below ; the flagellum is exposed at 

 each side of the rostrum. 



The walking legs diminish gradually in length from 

 first to last, and the difference in size is very considerable 

 among them. The terminal joint is not prehensile ; their 

 inferior border is smooth. 



Range. — Barbados, Santa Cruz ; in deep water. 



I, Trachymaia cornuta. 



Trachyinaia cornuta . A. Milne Edwards. 



The carapace granular and convex. It has a few 

 small spines. Upon the gastric region there are four 

 arranged in the shape of a cross. The anterior cardiac 

 lobe has two, situated in the middle line. The branchial 

 region has four or five spines. The lateral edge has a 

 row of short spines. The superior orbital border has a 

 spine directed forwards. The basal joint of the external 

 antennae has three small spines, one terminal, the two 

 others situated at the orbital border. 



The arm and forearm of the first pair of legs are 



