22 Bulletin, Vanderhilt Marine Museum, Vol. Ill 



mark the upper surface; tufts of long setae are set regularly along 

 these lines and on the lateral walls, especially anteriorly, where the 

 tufts are thicker and longer. 



The abdomen is coiled, soft, encased in a tough membrane, which 

 bears on its upper surface faint transverse indications of the fused 

 sutures ; the lateral regions bear many tufts of long setae ; the under- 

 side is transversely ribbed with folds of thickened skin ; the pretelsonic 

 segment is small, calcareous, the telson has the proximal part about 

 as long as the pretelsonic segment, both bear an approximately median 

 longitudinal groove; the distal part of the telson is unequal-sided, 

 heartshaped, the apex being pointed and on the left side, while the 

 right margin is slightly excavate. The rhipidura have a large, flexible 

 basal joint ; the inner blade large, its anterior margin convex, its pos- 

 terior lateral margin concave, the tip rounded, margins setose, the 

 upper surface covered with movable setae ; the posterior blade is very 

 small, but similar to the larger one. 



The ocular scale is rounded, wide at the base and tapers to an acute, 

 narrowly triangular tip which is directed obliquely inward. The 

 eyestalks are jointed, very flexible, elongate, slightly bulbous bas- 

 ally, evenly cylindrical through the greater part of their length, 

 dilating slightly just below the cornea, which is also dilated, terminal, 

 with a rounded, tongue-like projection of the stalk on the upper sur- 

 face of the cornea, tipped with a tuft of long setae. The eyestalks are 

 about 2 mm. shorter than the precervical region of the carapace, or 

 reach as far forward as the distal margin of the meral joint of the 

 chelipeds. 



The antennulae have the proximal joints stocky, situated beneath 

 the eyestalk ; the second joint is slender, reaching to midway the eye- 

 stalls ; the third joint is about one-third longer than the second joint ; 

 the flagellum is biarticulate, the longer branch being scarcely half the 

 length of the third peduncular joint. 



The antennae have the flagellum extending a half inch beyond the 

 tip of the great cheliped; the basal article is about as wide as long, 

 with the outer distal angle forming an acute tooth; the acicule is 

 narrow, elongate, twice as long as the first article is in the median 

 line, has the inner lateral margin denticulate, the tip very acuminate, 

 reaching to almost midway the length of the last pedunculate article ; 

 the second article is short, the third article is one-half as long as the 

 eyestalk, slender, laterally compressed; the flagellum is multiarticu- 

 late, slender, extending beyond the tip of the chelipeds. 



