Boone, Crustacea, Cruises of "Eagle" and "Ara," 1921-28 151 



rostrum, making a total of eight large and five small teeth on the 

 median carina and rostrum in addition to the apical spine. The cara- 

 pace is glabrous, with a small, acute, preorbital spine and immediately 

 behind this a longer, sharper preorbital spine. There is a less con- 

 spicuous suborbital spine and a very prominent antennal spine. The 

 abdomen has the third segment produced in the median posterior re- 

 gion, rounded, the remaining segments bent downward. The epimeral 

 plates of the first four segments are rounded, the fourth epimera also 

 having a slight tooth toward the posterior lateral region. The fifth 

 epimera are less evenly convex, with a more prominent tooth at the 

 postlateral angle. The sixth segment is longer than the fifth and has 

 a pair of submedian triangulate processes, one on each side of the base 

 of the telson ; the lower postlateral angle has a small spine. The telson 

 is as long as the caudal fan, with the distal margin bluntly rounded 

 and three pairs of submedian, articulated spines in longitudinal series 

 on the dorsal surface. Both blades of the caudal fan are rounded dis- 

 tally and ciliated, the outer blade the broader, with a sharp incision at 

 the subdistal tooth on the outer margin. 



The eye is prominent, hemispherical, with an ocellus. 



The antennulae have the basal article concave, elongated, with an 

 attenuated, acuminate, acicular-like process on the outer lateral bor- 

 der, its apex extending slightly beyond the segment; the second seg- 

 ment is short, with a spine at its outer distal margin ; the third article 

 is shorter than the second, with a very sharp spine at its upper distal 

 angle ; the flagella are short, the inner one slenderer and a little longer 

 than the short, thick outer branch which has a heavy brush of setae. 



The basal antennal article has two spines on the outer lateral mar- 

 gin, the second and third articles are slender, cylindrical and extend 

 about to midway the scaphocerite. The scaphocerite is as long as the 

 rostrum, with a tooth at the outer distal angle, the distal margin con- 

 vex and ciliated. 



The external maxillipeds are robust, long, extending slightly farther 

 forward than the scaphocerite and armed on the distal margin with 

 five or six strong, homy spines. 



The first legs are robust, when extended, reaching as far forward as 

 the tip of the scaphocerite; the merus, carpus and propodus are 

 swollen, convex, the fingers stocky, two-fifths as long as the palm, with 

 the tips horny, acute, the upper finger closing between the apices of 

 the bifid lower finger. 



The second legs are very slender, very long, when extended, reach- 



