Boone, Crustacea, Cruise of "Alva," 1931 227 



The superior antennae have the distal peduncular article re- 

 duced, the visible portion being about as long as the articles of 

 the flagellum and bearing a decided brush on the convex portion ; 

 the first and second articles of the flagellum are nearly subequal 

 in length, together forming two-thirds of the length of the pe- 

 duncular article; the first article is a little wider than the second 

 and bears a couple of bristles at the distal border; the second 

 article is nearly as slender as the conic, small distal third article, 

 which is equally long and bears a tuft of bristles distally. 



The inferior antennae are regrettably broken. 



The mouthparts are very similar to those of B. crusculum. 



The first gnathopods have the sideplates deeper than wide, 

 nearly a parallelogram, with the lower anterolateral angle 

 rounded and the postlateral angle more produced than the an- 

 terior one; the first joint of the gnathopod is short; the second 

 joint is the longest of the entire series and is decidedly bent or 

 arched; the third joint is less than half as long as the second, 

 widened distally, with a rounded node at the anterior lateral angle 

 distally; the fourth joint is greatly expanded, helmet-shaped, 

 with the superior lateral margin convex, the chela-forming in- 

 ferior apex greatly produced, the lower margin pectinate on the 

 proximal two-fifths and armed with five acute teeth, besides the 

 apical tooth; the anterior margin has nine teeth besides the apex; 

 the propodus has six teeth and three or four denticles in series 

 on the postlateral margin ; the anterior lateral margin is con- 

 vex ; the dactyl is short, acuminate, its length about equal to three- 

 tenths of the propodus and not produced as far as the apical tooth 

 of the opposed carpus. 



The second gnathopods have the sideplates much like those 

 of the first pair of gnathopods ; also the ischial and meral joints 

 are similar, except that the rounded lobe on the anterior distal 

 margin is larger in the second pair; the carpus is more widely 

 expanded transversely and produced on the anterior distal bor- 

 der into a convex lobe that projects beyond the base of the pro- 

 podus ; the inf erodistal angle is greatly produced, acute ; the in- 

 ferior lateral margin is pectinate on the proximal half and beyond 

 this armed with four sharp teeth besides the apex; the distal 

 margin bears ten or eleven smallish teeth in continuous series; 

 the propodus is scarcely two-thirds as long as the opposed distal 

 margin of the carpus ; the superior lateral margin is quite convex ; 



