[41] DECAPODA FROM ALBATROSS DREDGINGS. 385 



edge of the crest is truncated and sulcated longitudinally from the mid- 

 dle of the gastric region to the tip of the rostrum, or for nearly a third 

 of the entire length. The front projects straight forward in an acute 

 rostrum about half as long as the eye-stalk. Below the small orbital 

 sinus each sidf^, the short anterior margin is nearly vertical to the 

 base of the antenna, where it is at first longitudinal and then trans- 

 verse, leaving a broad open space opposite the efferent branchial i)assage. 



The eye-stalks are nearly two-fifths as long as the antenna! scales, 

 compressed vertically', about half as broad as long, and project in front, 

 just inside the cornea, in a small conical tubercle. The eyes are ap- 

 proximately hemispherical, though slightly compressed vertically, dis- 

 tinctly faceted, and colored with pigment which is dark brown in the 

 alcoholic specimens. The peduncle of the antennula is about three- 

 fourths as long as the antennal scale; the proximal segment is more 

 than half the entire length, and bears a squamiform lateral ijrocess, 

 which is concave on its outer surface and projects at its upper edge in 

 an acute tip reaching nearly as far forward as the body of the segment 

 itself; the middle segment is very short, and the distal about twice as 

 long. The inner or minor flagellum is very slender, subcylindrical, 

 and about as long as the carapax, while the outer is compressed and 

 expanded at the base, and much stouter than the inner. There is 

 an inconspicuous tooth below the base of the antennal scale, but other- 

 wise the peduncle of the antenna is unarmed. The antennal scale 

 is narrow, ovate, about two-fifths as long as the carapax, nearly a third 

 as broad as long, and stiffened by two longitudinal rib-like ridges on 

 the dorsal surface, one nearly median, the other parallel with and very 

 near the outer edge and terminating in the distal spine, which projects 

 beyond the narrow but obtusely rounded tip. The flagellum is some- 

 what compressed and approximately twice as long as the carapax. 



The second gnathopods (Plate VI, Fig. 7), are about as long as the 

 carapax and reach to the lips of the antennal scales: the coxa bears a 

 rudimentary epipod ; the basis is elongated and bears an exopod reach- 

 ing half way to the tip of the endopod, with the proximal segment of 

 which it is consolidated, as in the species of Pasiphae, the segment thus 

 formed (the antepenultimate) being nearly as long as the two distal 

 taken together, broader than they, strongly compressed in the middle, 

 and sparsely setigerous ; the two distal segments are slender and com- 

 pressed, the penultimate a little more than half as long as the ultimate, 

 and both armed on the inner side with setse which become spiniform 

 at the tip. 



The first perajopods reach by the tips of the autennal scales about half 

 the length of the chela?, and are smooth, nearly naked, and unarmed, 

 except the prehensile edges of the digits : the merus is a little shorter 

 than the antennal scale and strongly compressed ; the carpus a little 

 longer than broad, compressed, with the distal angles sharp; the chela 

 is longer than the antennal scale, the outer surface of the body slightly 

 S. Mis. 46 25 



