44 RATHBUN 
merus and distal end of ischium are also faintly segmented. The last 
three pairs of legs are very slender, and have slender, nearly cylindrical 
dactyli, which have only a few small spinules beneath near the base, and 
are contained between two and three times in their propodi. 
Abdomen more slender than in P. montagui tridens. Otherwise as in 
that species. 
Dimensions. —Female (off Cape Ann, Massachusetts), length 98 mm., 
carapace and rostrum 43.5 mm., rostrum 27.4 mm. 
Distribution.—Very common on the Atlantic coast of America from 
Nova Scotia to Chesapeake Bay in 15 to 321 fathoms. 
One specimen only has been taken in the Pacific, by the A/batross, off 
Shumagin Bank, Alaska, 138 fathoms, station 3339. 
PANDALUS PLATYCEROS Brandt. 
Pandalus platyceros BRANDT, in Middendorff’s Reise in den aussersten Norden 
und Osten Sibiriens, Band 11, Zool., Theil I, 123, 1851.—STIMPSON, 
Jour. Boston Soc. Nat. Hist., v1, 501 [61], 1857. 
Pandalus pubescentulus DANA, Crust. U. S. Expl. Exped., 1, 568, 1852; 
pl. XXXVI, fig. 8, 1855.—STIMPSON, Jour. Boston Soc. Nat. Hist., v1, 
501 [61], 1857.—KINGSLEY, Bull. Essex Inst., x, 63, 1878.—SMITH, 
Rept. Prog. Geol. Survey Canada, 1878-79, B, p. 214.—HOLMES, 
Occas. Papers Calif. Acad. Sci., VII, 210, 1900. 
Body stout. Carapace covered with a dense, short pubescence. 
Rostrum one and a half to one and two thirds times the carapace, pro- 
vided with a broad entire laminar crest on each side. Median crest 
arising half-way back on the carapace, armed with 14 to 17 spines ex- 
tending to middle of rostrum, the anterior 1 to 5 fixed, the rest movable; 
usually a solitary spine not far behind the acute tip; lower limb armed 
with 7 or 8 fixed spines, diminishing gradually in size; the basal tooth 
very large. Posterior part of rostrum deflexed, anterior half or two 
thirds ascending, tip above level of carapace. Antennal spine very 
strong; pterygostomian small, but well marked. 
Eyes large, pyriform; cornea in alcohol light greenish; ocellus black. 
Antennular peduncle reaching two fifths the length of acicle, second 
and third joints subequal; outer flagellum one half longer than carapace, 
its basal half thickened; inner flagellum a little longer; outer basal scale 
reaching nearly to end of first joint. 
Antennal scale four fifths to seven eighths as long as carapace, oblong, 
extremity of blade subtruncate, slightly exceeded by the spine; peduncle 
reaching nearly to the middle of the third segment of antennular 
peduncle; flagellum stout at base, equaling or exceeding length of body. 
Maxillipeds stout, reaching nearly or about to end of antennal scale; 
first pair of feet to middle of terminal joint of maxillipeds. Right leg of 
