i8o 



DISCOVERY REPORTS 



The specimens vary from being entirely smooth to being finely thorny along the 

 distal edges of the outer brachials and very finely so along the distal edges of the pinnulars 

 (Fig. 15 b). 



Fig. 15. hometra vivipara. a, cirrus, b, distal brachials, r, proximal part of an arm with Pj and Pj. 

 d, a middle genital pinnule of a female, e, a middle genital pinnule of a male. /, well developed side- and 

 cover-plates of distal pinnule, g, P, of the female from the Bransfield Strait, a and c, x 11; b, d, e, and g, 

 X 13. /, x6o. 



Pi is always longer and usually stouter than P., , and P3 is usually slightly shorter than 

 P2 . Pi is of 10-17, usually 10-13, segments, and 5-9 mm. long. It is not free proximally, 

 for its first four to six segments are closely attached to the disk, and the next one or two 

 are connected by a web of tissue with the disk (Fig. 1 5 c). It is sometimes much stouter 

 than P2 with its basal segments strongly compressed so that they are keeled dorsally; 

 it is sometimes only slightly heavier with none of its segments compressed. The basal 



