Boone, Crustacea, Cruise of "Alva," 1931 37 



Technical description : The carapace is much longer than 

 its maximum width, which is two-thirds of the length; the pre- 

 cervical portion is well calcified, marked by several longitudinal 

 grooves and with a distinct, large, triangular rostrum, the tip of 

 which barely touches the bases of the ophthalmic scales ; a trans- 

 verse groove defines the base of the rostrum and extends back- 

 ward on the carapace on either side. The anterolateral angles of 

 the carapace are rounded and the lateral margins are heavily 

 fringed with coarse golden setae, which are also abundant across 

 the front, on the basal articles of both pairs of antennae, the oph- 

 thalmic scales and eyestalks. Similar setae and shaggy bristles, 

 red or yellow, occur on the chelipeds and legs. The postcervical 

 portion of the carapace is widest across the branchial region, which 

 is unusually well calcified and separated medially by a hard, longi- 

 tudinal plate. 



The ophthalmic scales are approximated, slightly separated 

 distally, with the tips each cut into three or four smooth, conical 

 teeth. The eyestalks are equal in length to the antennular pe- 

 duncle, but are slightly shorter than the width of the frontal mar- 

 gin ; the eyestalks are slightly dilated below the cornea, which is 

 terminal, wide, hemispherical. There are ten to twelve clusters 

 of bristles on the upper surface of the eyestalks. 



The antennular peduncle is semiconcealed beneath the shaggy 

 bristles on its dorsal surface; the flagellum is two-branched, the 

 thicker, upper branch consists of about thirty rings and has a 

 heavy, soft brush of setae on the under surface ; the lower branch 

 is much slenderer, consists of only about twenty rings, each of 

 which bears a small, solitary bristle. 



. The first peduncular article of the antennae is short and wide, 

 produced to a point on the outer side of the acicule, and beneath 

 the acicule is produced on the inferior inner side to an elongate 

 process that extends entirely beneath the second joint for its 

 entire length ; the latter is short, concealed dorsally by the acicule, 

 which protrudes above the proximal two-fifths of the elongated 

 third article ; this acicule is very narrowed, pointed, distally spi- 

 nose ; the flagellum is thickish, extending to the tip of the cheliped 

 and is beset with several fine, short setae on the distal margin of 

 each ring. 



The chelipeds are equal, short, the ischium produced to a short, 

 blunt tooth on the inferior distal margin, interfitting into a cavity 



