72 Bulletin Vanderbilt Marine Museum, Vol. VI 



Technical description : According to Dr. Alcock, who had 

 nearly three hundred specimens for examination, this species rare- 

 ly attains a length of six and one-half inches. The longest of the 

 "Alva" specimens is only about two-thirds of this size and has 

 the body covered with a coarse short pilosity, which is arranged 

 in a definite pattern on the abdominal terga, having interrupting 

 transverse bands of non-pilose, glabrous exoskeleton. The cara- 

 pace is entirely pilose, except in the grooves. The rostrum is short, 

 not quite extending to the distal margin of the antennular pe- 

 duncle, nearly straight, with the distal portion slightly, almost 

 unnoticeably, elevated. The rostral carina extends almost, or 

 quite to the posterior margin in some specimens. There is a weak 

 epigastric tooth, not quite in line transversely with the hepatic 

 tooth, being slightly posterior to it and there are nine stronger, 

 subequal teeth, the proximal one of which is well in advance of 

 the epigastric tooth yet is above the carapace, about opposite to a 

 small, transverse groove which runs obliquely out from the side 

 of the rostrum. The second rostral tooth is about half as far in 

 advance of the first tooth as the latter is from the epigastric tooth. 

 The remaining rostral teeth are nearly subequally spaced, the 

 distal two being a very little closer together than the others ; the 

 distal tooth is very near the tip of the rostrum. The lateral rostral 

 sulcus extends from beside the distal rostral tooth backward be- 

 hind the epigastric tooth for a distance about as far as the space 

 between the epigastric tooth and the first rostral tooth. There is 

 a short oblique sulcus extending outward from the side of the 

 rostrum, below the first rostral tooth, to a point behind the base 

 of the obscure postorbital ridge, which in reality is not a ridge 

 but a tumid elevation behind the minute orbital spine. The anten- 

 nal spine is strong and the postantennal carina is also strong, 

 smooth, continued back almost to the anterior margin of the 

 related postantennal sulcus which is posteriorly continuous with 

 the tomentose, hepatic sulcus. The hepatic spine is strong, acute, 

 and the cervical groove above it is continued about one-half way 

 to the dorsal carina as a sharply defined groove. The sinuous 

 subhepatic groove, which is the anterior continuation of the cer- 

 vical groove, is even deeper-channeled than the upper branch and 

 is continued anteriorly almost to the anterolateral margin. The 

 posthepatic carina is strong and is continued as a strong, flat, 

 sinuate carina almost to the posterior margin. Below this, defin- 



