30 G. 0. SARS. [SEC. ARC. EXP. FRAM 



armed at the tip with a slender claw and a still longer seta accom- 

 panied by a small bristle. .Natatory legs normal. Last pair of legs of 

 moderate size, distal joint obovate in form, with 6 not very long mar- 

 ginal seta?; inner expansion of proximal joint triangular, and scarcely 

 extending to the middle of the distal joint, marginal seta3 5 in number. 



Length of adult female 0.87 mm. 



Remarks. In its general form this species somewhat resembles 

 A. similis (GLAUS). It is, however, of smaller size and moreover differs 

 conspicuously in the structure of the first and last pairs of legs. 



Occurrence. - - Some few specimens of this form occurred in a 

 bottle of specimens taken on July 30, 1900 (the exact locality not indicated). 



108. Amphiascus polaris, G. 0. SARS, n. sp. 

 (PI. VIII, figs. 5-10). 



Specific Characters. Female. Body less slender than 



in the preceding species and of nearly uniform width throughout. 

 Rostrum considerably prominent and exserted to a very acute point. 

 Urosome not attaining the length of the anterior division, last segment 

 scarcely shorter than the preceding one, and deeply incised behind. 

 Caudal rami short and rather distant, inner medial seta slightly dilated 

 at the base and nearly twice as long as the urosome. Anterior an- 

 tennae rather slender, 8-articulate, with the 4th joint much longer than 

 3rd, terminal part about equalling in length those joints combined. 

 1st pair of legs with the rami very unequal, the outer one scarcely 

 exceeding half the length of the inner, and having all 3 joints of about 

 equal size, the last one, as in A. congener, armed with 3 spines and 

 2 geniculated setae; inner ram us with the 1st joint very slender and 

 slightly curved, seta attached inside its end unusually long, outer 2 

 joints very unequal, the last one being almost 3 times as long as the 

 other and linear in form, carrying on the tip a slender, evenly curved 

 claw and a still longer seta accompanied by a small bristle. Natatory 

 legs with the rami more slender than in the preceding species, other- 

 wise of normal structure. Last pair of legs somewhat resembling those 

 in A. congener, distal joint, however, less dilated, and oblong in form; 

 inner expansion of proximal joint extending to about the middle of the 

 distal joint, and having the 2 innermost seta? comparatively short and 

 spiniform. Ovisacs oblong oval in form, and containing only a limited 

 number of ova. 



Male with the inner ramus of 2nd pair of legs transformed in the 

 usual manner, the 2 outer joints, being wholly coalesced, outer edge 



