268 



COLE 



bristles along the dorsal curve ; cl. strong, fully half as long as ts.-2, but 

 slightly curved; aux. cl. well developed, half as long as cl. Legs of 

 female nearly smooth, a few small bristles, especially on the dorsal 

 side of/., /.i, and /.2 ; male considerably more spiny, especially on coxal 

 joints. 



Length of male about 3 mm., extent about 13 mm.; female slightly 

 smaller. 



As shown in the following table, the localities at which this species was 

 taken were two Orca, in Prince William Sound, and Popof Island, in 

 the Shumagin group. Those at Orca were found on Thuiaria turgida 

 Clark.* 



SPECIMENS EXAMINED. 



Remarks. This species resembles Ammothea lavis (Hodge) as de- 

 scribed by Sars ('91, p. 124, pi. xin, fig. 2, a-m), especially in lacking 

 the very spiny character of many of the species of the genus. It appears, 

 however, to be distinct from A. l&vis. Among other differences may be 

 noted the following: A. alaskensis has but one protuberance on the 

 lateral processes, in place of two ; the eye tubercle is much smaller, 

 with the eyes of the same size; the proboscis is considerably larger in 

 proportion and of a different shape ; the chelifori are not half as long as 

 the proboscis, and the basal joint has a prominent dorsal process ; the 

 second joint of the palpi is not shorter than the fourth ; the auxiliary 

 claws are much better developed. A. alaskensis is also about twice the 

 size of A. Itzvis. 



No immature specimens of A. alaskensis were found. 



Rather thickly scattered over the surface of one of the specimens 

 from Orca, and especially on the palpi, was observed a peculiar elliptical 

 diatom, and it was of interest that the same form was found on one of 

 the specimens from Popof Island, some six or seven hundred miles to the 

 westward. Two or three other species of diatoms were also clinging to 

 the latter. The first-mentioned diatom has also been observed on other 

 species of Pycnogonida. 



1 1 am indebted to Professor C. C. Nutting for the identification of this Hydroid. 



