ANCET3S MAXILLARIS. 191 



inner apical angle produced into a slender elongated 

 process, followed by four joints attached together 

 obliquely, with a strong coating of bristles directed 

 obliquely backwards along their outer margin. The first 

 and second free segments of the body are about the same 

 width as the head, short, transverse, with the sides rather 

 rounded and dilated ; the three following segments are 

 somewhat narrowed, longer, much more irregular, and 

 less distinctly separated from each other than the anterior 

 segments, and with the lateral margins rounded and 

 directed somewhat backwards. There is a small short 

 transverse piece in the middle between the last segment 

 of the body (pereion) and the first segment of the tail 

 (pleon). The pleon is about equal to two-thirds of the 

 length of the head, and consists of five transverse seg- 

 ments, followed by a triangular central terminal plate, 

 each segment being furnished on each side beneath with 

 two pairs of very delicate, strongly ciliated, branchial 

 scales. The tail (pleon) is not half the width of the 

 hind part of the body. The legs are of moderate length 

 and rather robust, with some small tubercles on the inner 

 margin of the middle joints. 



The female, in its fully developed gravid state, as 

 represented in the following page, is a little longer than 

 the male, and has the body greatly swollen with eggs, or 

 young ; the head, anterior segments of the body, and tail 

 being small, and marked all over with minute dark points. 

 The head is subtriangular, without any appearance of the 

 immense jaws of the male (of which, indeed, we have not 

 found the slightest vestige). The upper antennae are 

 small, and consist of a short basal joint, followed by two 

 nearly equal longer joints, and a short and slender ter- 

 minal flagellum. The lower antennae are much stronger 

 and longer than the upper, and consist of two strong 



