Boone, Crustacea, Cruise of ''Alva," 1931 83 



vical, urogastrie and cardiac depressions are well defined. There is a 

 slightly beaded, curved, granular line across the mesogastric region, 

 just anterior to the heavy carina that extends inward from the second 

 lateral spine. A similar transverse line runs across the middle of the 

 cardiac region. The summit of the granular region is slightly tumid 

 and very granulose. The male belt is triangular and is composed of 

 five articles, the third, fourth and fifth segments being fused. The 

 second and third segments are conspicuously carinated transversely. 

 The sternal plastron is wide and is finely granular on its anterior half, 

 less so, practically smooth posteriorly. 



The excurrent channel forms a distinct wide groove, below and 

 subparallel to the inferior orbital margin. 



The eyestalks are very long, slender, slightly tapered distally, ex- 

 tending from the frontal septum to the base of the anterolateral spine, 

 at which point the flexible joint unites with the large, black ovoid cor- 

 nea, which is attached at one end obliquely distally. 



The antennulae have the first peduncular article thick, situated 

 within the f ossett ; the second and third articles are very slender, cy- 

 lindrical, the flagellum is short, less than one-third the length of the 

 preceding article, multiarticulate and tipped with a tuft of fine setae. 

 When fully extended, the antennulae reach one-third of the length of 

 the eyestalk. 



The antennae are rudimentary with the basal article curiously 

 thickened and produced, fitting into the orbital hiatus. The second 

 and third articles are short, bulbous; the flagellum is composed of 

 thirty or forty fine tapered thread-like annulations and when ex- 

 tended, is about half as long as the eyestalk. 



The external maxillipeds are very close-fitting, the exognath a 

 long, slender rod, with a multiarticulate whip. The ischium of the 

 endognath is subrectangular with a longitudinal sulcus on the outer 

 surface which is very granulose. The inner lateral margins of both 

 ischium and merus have a dense fringe of golden setae ; the merus has 

 the inner distal angle obliquely truncated, for the reception of the 

 palp and the outer distal angle evenly rounded not produced; the 

 three-jointed palp is quite large, the distal article beset with golden 

 setae. The margins of the buccal cavern also are fringed with setae. 



The chelipeds are equal in the male and are very long and slender, 

 being three and one-half times the length of the carapace ; the ischium 

 is rather well developed, trigonal ; the merus also trigonal, is one and 



