GENUS — POLLICIPES. 297 



on their inner edges, but this is not invariable. The olfac- 

 tory orifices in most of the species are highly prominent. 

 Cirri. — The first pair is never placed far distant from 

 the second. The posterior cirri have strong, somewhat 

 protuberant segments ; and between each of the four or 

 five pair of main spines (PL X, fig. 27), there is a rather 

 large tuft of straight, fine, short bristles. The second and 

 third pair have the basal segments, either of the anterior 

 rami, or of both rami, so thickly clothed with spines 

 (fig. 25), as to be brush-like : in P. mitella, however, the 

 third pair is like the three posterior pair in the arrange- 

 ment of its spines, in this respect resembling the sessile 

 Chthamalinae. The caudal appendages are either uni- 

 articulate and spinose, or multi-articulate : it is remark- 

 able that there should be this difference in such closely 

 allied species as P. cornucopia and P. poli/merus : the 

 short, obtuse, obscurely-articulated caudal appendage of 

 the former species (fig. 22) makes an excellent passage 

 from the uni-articulate (fig. 19) to the multi-articulate 

 form, as in P. mitella. 



The stomach, in those species which I opened, is desti- 

 tute of caeca ; the hepatic glands are arranged in straight 

 lines ; the rectum is unusually short. The prosoma is well 

 developed. 



In P. cornucopia, P. elegans, and P. polymerus, there 

 are numerous filamentary appendages both on the pro- 

 soma, and at the bases of the first pair of cirri: these 

 appendages are occupied by testes, and I suspect stand 

 in relation to the length of the peduncle and consequent 

 great development of the ovaria. In order to give space 

 for the filamentary appendages, the sack (generally rough- 

 ened by small inwardly-pointing papillae) penetrates more 

 deeply than usual into the upper part of the peduncle. 

 There are small ovigerous fraena in P. sertus, P. spinosus, 

 and P. mitella ; in the three other species, the fraenum or 

 fold occupies the usual position on each side, and is large ; 

 but in one specimen carefully examined by me, I was 

 unable to see any glands ; and in another specimen, the 



