Boone, Crustacea, Cruises of "Eagle" and "Ara," 1921-28 107 



obliquely forward, upward and outward and prolonged decidedly be- 

 yond the ventral surface of the basal article of the antennae; the 

 orbital margin is provided with four teeth, one superior, situated in 

 front of the closed sinus, one inferior belonging to the antennal base, 

 one preocular and one postocular. There is a pair of low tubercles, 

 one each in the prominence of the protogastric region, a strong, me- 

 dian, upward directed spine on the gastric and in line with this, a 

 similar subequal spine on the cardiac region, and a slightly smaller, 

 outward-directed spine on the intestinal region but so far back that it 

 projects beyond the posterior margin. There is a pair of low tubercles, 

 each one the summit of the branchial region. There is a pair of 

 strong outward and posteriorly directed spines at the postlateral angle 

 and parallel to the cardiac spine. The outer antennae have the basal 

 article decidedly enlarged, and a spine near its lower distal angle, 

 another suborbital, and a long one projecting outside the second an- 

 tennal joint; the second and third joints are subequal, slender, their 

 combined length being less than that of the rostrum ; the antennae con- 

 sist of about eighteen long, slender, subequal articles, each of which 

 is armed with several very long tactile hairs. The inner antennae 

 have their massive basal joint situated within the septum; the two 

 slender, somewhat cylindrical joints, of which the first is longer, fold 

 upon each other and fit within the antennal septum ; the brief, biram- 

 ous fiagellum is composed of a minor branch consisting of five rings 

 and a stouter conically formed branch consisting of eleven rings and 

 furnished with a dense brush of setae. 



The external maxillipeds have the ischium much longer than the 

 merus and furnished along the inner margin with both conical teeth 

 and long, curved, spinelike hairs ; the merus is rather wider than long 

 with the distal border somewhat flaring; there is an incision at the 

 inner distal angle, from which arises the subequal, tapering, three- 

 jointed palp; the exognath reaches almost to the distal angle of the 

 merus and bears a concealed, long lash. There are four tubercles on 

 the pterygostomian region. 



The chelipeds are equal in both sexes, long, slender, depressed cylin- 

 drical. The coxa is short, stout and on the ventral surface has a small 

 node which interlocks in a process of the sternal plate; the basis is 

 very small, the ischium situated ventrally and produced distally to 

 a rounded, triangular point ; the merus is very long and armed with 

 four longitudinal rows of tubercles ; the dactyli subequal, gaping, the 

 upper slightly more curved than the lower ; the upper dactyl bears a 



