Species of the Amphipodan (7e«us Cyproidia. 243 



Cyproidia otakensis, sp. n. (PL V.) 



Specific description. — Ceplialon with a very small blunt 

 rostral projection ; first two segments of pereion short, 

 third and fourth much longer, fourth longer than the third ; 

 last three segments of pereion and first three segments of 

 pleon subequal in length; fourth segment of pleon fully as 

 long as the third, but much narrower, it bears throughout its 

 length a distinct dorsal crest, which widens posteriorly and 

 projects beyond the end of the following segment, ending 

 acutely; fifth segment very short, only about one fiflh the 

 length of the fourth, sixth segment longer than the fifth ; 

 telson reaching to the extremity of the peduncle of the 

 terminal uropods. Gnathopoda subequal; carpus of the 

 second longer than that of the first, and in both produced 

 distally along the underside of the propodos ; propodos of the 

 second rather the stouter, palm not well defined in either. 

 Basa of first and second pereiopoda narrow, not expanded; 

 those of third, fourth, and fifth all expanded in a thin flat 

 plate with rounded posterior margin. Kami of terminal 

 uropoda unequal, upper margins fringed with fine setai and 

 a lew stouter spinules at intervals. 



Colour light brown. 



Size. Length of body about 3 millim. 



Hah. Otago Harbour, New Zealand. A few specimens 

 obtained by surface-netting. 



In addition to the above brief diagnosis, I give here the 

 following additional details : — 



The general shape of the hody will be best seen from the 

 figure ; the side-plates of the first and second pereiopoda are 

 enoimously developed, and the antennas, appendages, and 

 pleon can nearly all be concealed and protected by them. 

 The side-plate of the first pereiopod extends forwards past 

 the first two short segments of the pereion and fits closely 

 along to the lower margin of the cephalon ; its junction with 

 the side-plate of the second pereiopod is sinuous, the two are 

 accurately and closely fitted, but are not actually cemented 

 together, and can be readily separated by dissection. The 

 side-plate of the second pereiopod is slightly deeper and con- 

 siderably broader than that of the first ; its margin is regu- 

 larly convex below and behind, but is excavated at the upper 

 posterior corner for the reception of the fairly well developed 

 side-plate of the third pereiopod. 



The cephalon is rather longer than the first segment of the 

 pereion, the rostrum small and indistinct. The eye is large 



16^ 



