Boone, Crustacea, Cruises of "Eagle" and "Ara," 1921-28 155 



seventh and eighth teeth are similar to those preceding but have the 

 tips more acuminate; that of the eighth tooth directed slightly for- 

 ward ; the ninth or lateral tooth is strong, acuminate, directed slightly 

 upward and forward and outward. There is a fringe of setae beneath 

 the teeth of the anterolateral margin. The dorsal surface is mod- 

 erately convex, with the regions clearly delineated, the urogastric and 

 cervical grooves being the most prominent. There is a fine carina 

 formed of granulations extending across the carapace and out onto 

 the lateral spine ; there is a similar, shorter carina anterior to this on 

 the gastric region. The postlateral and posterior margins are lightly 

 carinated. The male abdominal belt is narrowly T-shaped, five-seg- 

 mented, the first segment very short, obscure ; the next segment short 

 but wide, filling the space between the fifth pair of legs and with a 

 sharp, median, transverse carina; the third and fourth segments are 

 completely fused, a sharp transverse carina on the third segment ; the 

 fifth and sixth segments are narrow, fused, but retain a suture line 

 indicating the fusion ; the seventh segment is triangulate with the tip 

 rounded. The sternal plaston is wide, flattish, with the suture lines 

 sharply defined. 



The external maxillipeds have the ischium subrectangular, the distal 

 margin slightly sinuate, the inner lateral margin fringed with short 

 setae ; there is a decided longitudinal sulcus on the outer face of the 

 ischium ; the merus is three-fourths as long as the ischium and has the 

 outer distal angle produced and rounded; the inner dostal angle is 

 obliquely excavate for the reception of the palp, which is composed 

 of three joints of subequal length but of gradually decreasing width. 



The eyestalk is short, constricted below the cornea, which is ter- 

 minal, subspherical and directed upward. 



The antennulae fold transversely in the septum, which is divided 

 by a strong median tooth; the basal article is enlarged, the free ar- 

 ticle slender. 



The antennae have the basal article anchylosed, produced into a 

 tooth-like cusp in the orbital sinus ; the second and third articles are 

 slender, successively smaller; the flagellum is very slender and is 

 equal to one and one-half times the long diameter of the orbit. 



The ehelipeds are subequal; the merus is three-sided, with three 

 acute spines on the anterior margin; the carpus is slightly elongate, 

 convex, with a subdistal tooth on the outer lateral margin from which 

 an oblique carina runs back along the lower margin ; above this there 

 is a second carina, and on the upper face there are two short granular 



