104 



RATHBUN 



strongly arched over the eye, and armed with 12 to 14 small teeth; the 

 posterior 3 or 4 behind the orbit, the posterior 2 distinctly separated from 

 the others ; the hindermost is much depressed, obsolescent ; the distal 



third of the rostrum is 

 straight, either horizon- 

 tal or slightly deflexed, 

 acute, unarmed above, 

 furnished with i or 2 

 .teeth below; lower limb 

 very narrow. Antennal 

 spine well developed, 

 pterygostomian very 

 small. 



Eyes large, pyriform. 



FIG. 47. Spironiocaris avina. Station 2853. a. Side of carapace Antennular peduncle 

 (X 3)- * Dorsal view of anterior portion (X 4>- extending tWO thirds 



the length of the antennal scale, second segment three times as long as 

 third, outer basal scale suberect and not reaching end of first segment ; 

 flagella subequal in length ; thickened part of outer one extending half 

 its length beyond antennal scale. Outer margin of antennal scale a 

 little more than two thirds as long as carapace, scale tapering, distal 

 margin very oblique, peduncle extending quite to middle of scale and 

 nearly to end of second segment of antennular peduncle. 



The outer maxillipeds extend beyond the scale by nearly half the 

 length of their last segment. First pair of feet reaching half-way 

 between antennal peduncle and end of scale; second pair exceeding 

 maxilliped by the length of the propodus and the last joint of the carpus ; 

 third to fifth pairs nearly equal, the fifth pair overreaching the second 

 pair ; dactyli very slender and unarmed. 



Abdomen smooth; fourth segment furnished with a lateral spine; 

 sixth segment a little less than twice as long as fifth, and shorter than 

 seventh, which bears 3 spinules on each side. 



Male. Smaller, more slender, and has slightly longer antennulae than 

 the female. 



Dimensions. Female, length 35 mm., length of carapace and rostrum 

 12 mm., of rostrum 3.5 mm. 



Distribution. From Pribilof Islands to Oregon, 41 to 351 fathoms. 

 Taken exclusively by the Albatross, at the following localities : 

 Off Pribilof Islands, 60-184 fathoms, stations 3484, 3485, 3489, 3494, 



3605, 3609. 

 North of Unalaska, 165-351 fathoms, stations 3315, 3317, 333 



locality), 3331. 



