DECAPODS 53 



one seventh to one and a half times the length of the rest of the cara- 

 pace, ascending. Anterior two thirds of carapace furnished with a 

 median crest. Median spines 8 to 13, four to six of which are behind 

 the orbits, the insertion of the posterior spine being at the middle of 

 the carapace ; the anterior spine is behind the middle of the rostrum ; 

 this is exclusive of a sub terminal spine. Inferior spines 8 to 12. 



The peduncle of the antennula extends a little past the middle of the 

 antennal scale ; the second segment one and a half times as long as 

 third ; outer flagellum two thirds as long as body, inner flagellum shorter. 



Peduncle of antenna reaching to end of second antennular segment ; 

 scale three fourths to four fifths as long as carapace, broader behind than 

 in P. ampla; flagellum one and a half times the length of the body. 



The outer maxillipeds extend either to the tip or nearly to the tip of 

 antennal scale; the first pair of pereiopods overreach the penultimate 

 segment of the maxilliped; second pair subequal, extending beyond 



acicle, carpal segments 18 to 21, chela equal in length to ^-^ 



five and a half or six of the adjoining segments of the fc=^ ^ 



. , . ,, . . FIG. 16. Pandalopsis 



carpus ; palm more than one and a half times as long as aieutica. chela of 9 

 fingers. There is very little difference in the length of <X "^ 

 the third, fourth, and fifth pairs of feet ; the third pair reaches beyond 

 the acicle by the length of the dactylus and half the propodus ; the dactyli 

 are contained about five and a half times in their propodi. 



The pleon is much like that of P. ampla; the pleura of the second seg- 

 ment are narrower than in P. ampla; the sixth segment is shorter, only 

 twice as long as wide. 



For the rest, as in P. ampla. 



Dimensions. Adult female, length 132 mm., length of carapace and 

 rostrum 61.5 mm., of rostrum 33 mm. 



Distribution. Over one hundred specimens were taken by the Alba- 

 tross at station 3480, off Seguam, Aleutian Islands, 283 fathoms (type 

 locality). North of Rat Islands, Aleutians, 270 fathoms, station 3785. 



Affinities. Besides its resemblance to P. ampla t this species is also 

 similar to P. lamelligera (Brandt), from Kamchatka, but differs in the 

 fewer dorsal spines, in the longer feet of the first pair, and in the nar- 

 rower pleura of the second segment of the pleon. 



PANDALOPSIS LONGIROSTRIS Rathbun. 



Pandalopsis longirostris RATHBUN, Proc. U. S. Nat. Mus., xxiv, 902, 1902. 



Male. Surface smooth. Rostrum a little more than twice as long as 



the carapace proper, strongly ascending, and continued backward in a 



