MUSEUM OF COMPARATIVE ZOOLOGY. 59 



verse punctate ridges, which give rise to very short bristle-like hairs, while in 

 P. Montagui, proptnquus, and borealis the surface is naked and very smooth. 

 The carapax is considerably more slender than in P. Montacjui, and the pos- 

 terior tooth of the dorsal carina is farther forward, being much in front of the 

 middle. The abdomen is more slender than in P. Montaijui ; but, except for 

 the greater slenderness, there is scarcely any diflerence in the form or propor- 

 tions of the somites, or the form and armature of the telson and uropods. 

 There are slender exopods, about a third as long as the ischia, at the bases of 

 the external maxillipeds, but the endopods themselves are as in P. Montagui; 

 the merus reaches to the base of the flagellum of the anteima, and the tip falls 

 considerably short of the tip of the antennal scale. 



The legs of the first pair are nearly as in P. Montagui. The right chelate leg of 

 the second pair is shorter and stouter than in P. Montagui, and scarcely reaches 

 the tip of the corresponding leg of the first pair ; the ischium is about a fourth 

 the entire length ; the merus is only a little shorter than the ischium ; the 

 carpus increases in thickness distally, is a little longer than the ischium, not 

 more than about once and a half as long as the merus, and usually composed 

 of only five segments, the proximal half being wholly unsegmented or annu- 

 lated, then three subequal and very distinct segments, about as broad as long, 

 and these followed by the terminal segment, which is about as long as the 

 three next preceding ; the chela is about half as long as the carpus, and a little 

 stouter than its distal end. The left chelate leg is a little shorter and stouter 

 than in P. Montagui, but has about the same number of segments in the merus 

 and carpus, and does not difi'er in other respects. The third, fourth, and fifth 

 pairs of legs differ from those of P. Montagui in being a little more slender, and 

 in having much longer, much more slender, and nearly cylindrical dactyli, 

 which are wholly unarmed, except a few small spinules beneath near the base. 



The branchial formula is the same as in P. Montagui. 



Pandalus tenuipes Smith. 



Proc. National Mus., "Washington, III. p. 441, 1881. 



Plate XIII. Fig. IS. 



Station 314, N. Lat. 32° 24', W. Long. 78" 44', 142 fathoms ; one male and 

 one young specimen, both imperfect. 



This species is smaller but has a proportionally thicker body than P. Mon- 

 tagui, and the surface of the carapax and abdomen is very minutely roughened, 

 somewhat as in P. leptocerus, but the punctate ridges are much less conspicuous 

 and much more thickly, crowded than in that species. 



The carapax, including the rostrum, is about two fifths of the entire length, 

 and the carapax proper is nearly as long as the rostrum, slightly swollen in the 

 middle, somewhat contracted in front, as seen from above, and with the rostral 

 carina extending back to about the middle, and armed, at about a third of the 



