74 REPORT OF COMMISSIONERS OF INLAND FISHERIES. 



half tapering abruptly and plumose exteriorly; outer seta one fourth 

 as long as inner, plumose exteriorly. 



Female: — First antenna short, less than half as long as the head 

 segment, and six-jointed; 1st joint large, quadrate, with a row of 

 coarse spines on the inner side of its upper surface; 2nd joint as broad 

 as the first, very short, and prolonged in front into a rounded promi- 

 nence fringed with blunt spines; 3rd joint smaller, bearing on its 

 anterior distal angle a large esthetask, one third longer than the 

 antenna, and supported by a 2-jointed accessory branch; 4th, 5th, 

 and 6th joints small, about equal, and bearing a number of bristles. 

 Second antenna longer and heavier than the first, three-jointed; 

 1st and 2nd joints large, a little longer than broad, the 2nd spined 

 on the upper edge at the end; 3rd joint more slender, bearing six 

 strong, curved spines of unequal length. Mandibles and maxillae 

 reduced and adapted for sucking. Mandible pointed at the end, 

 bearing a two-jointed palp and forming with its mate a tube-like 

 trough. First joint of palp small ; 2nd joint elongated and bearing two 

 bristles, one slender and long, the other shorter and plumose on both 

 edges. First maxilla (?) about a third as long as the mandible, and 

 similar in shape, but with two or three slender teeth at apex. The 

 maxillae appear to be partially enclosed in the mandibular tube. The 

 2nd maxilla was not found. The maxillipeds are partially united, hav- 

 ing a common quadrate basal joint; each branch is further made up 

 of two joints, the first long and slender, the second minute and bearing 

 a rather long seta. 



The basipodite of the 1st foot is formed of two broad, heavy joints, 

 each spinose anteriorly, the second with two heavy curved spines at 

 the distal angles; inner ramus 2-jointed, the 2nd joint somewhat 

 longer than the first, with two terminal spines, the inner about a third 

 longer than the outer and slightly plumose on the outer side; outer 

 ramus 3-jointed, twice as long as inner, each joint spinose distally and 

 with a strong curved spine at the external distal angle, last joint with 

 two additional terminal spines. Second to 4th feet alike, both rami 

 3-jointed and with slender setae sparingly and delicately plumose. 



