]i)10.] OSTIIAC'ODA I'HUM I'AXOAWTKA. 7 'Mi 



Ejaculatory tulies each with eiijht wliovls of ehitinous stripes, both 

 extremities conspiciiousl 3' rlilateil and encircled by a row of coarser 

 spiniform processes. 



Remcu-ks, — The t3'pe of this new genns is the form described 

 by the present aiitlior from a brackish -water lagoon on the 

 Chatham Islands under the name Paracypris tenuis*. It was, 

 indeed, oidy with gieat doubt that I provisionally' refeired this 

 form to the marine genus Paracyjiris G. O. tSars. I now find 

 tha.t it is much more closly i-elated to the genus Cypria Zenckei-, 

 for which reason I propose to name the new genus Paracypr'ui. 

 The species fiom the Chatham Islands is closely allied to some 

 of the Taiiganj'ika species, as will be shown below. No less than 

 twelve different species referable to this genus have been found 

 in the samples. 



1. Paracypria declivis, sp. n. {Plate LXIY. figs. 1-8.) 



Sp)ecifijG Characters. — Female. Shell moderately compi'essed : 

 seen latei'ally (fig. 1) of oblong cuneiform shape, greatest height 

 occurring somewhat in front of the middle and not attaining 

 half the length, anterior extremity obtusely rounded, posterior 

 much narrower and ending below in a somewdiat conical blunt 

 corner, dorsal margin strongly curved in the middle and sloping 

 evenly behind to the posterior corner, venti'al margin nearly- 

 perfectly str-aight ; seen dorsally (fig. 2) narrow oblong in form, 

 with the greatest width about equalling one-third of the length, 

 both extremities acumina,te, side-edges nearly parallel in the 

 middle. Yalves only slightly unequal and very thin and pellucid, 

 with very slight tiace of hairs at the extremities. Surface of 

 shell quite smooth and shining, without any distinct sculptuiing. 

 Limbs (figs. 4, 5), on the whole, very like those in the t^'pe 

 species ; the slender dactylus of the anterior legs (fig. 4), how- 

 ever, quite ;smooth, without any trace of lateral denticles. 

 Caudal rami (fig. 6) slightly curved at the base; claws lather 

 strong and perfectly smooth, the distal one much the larger and 

 exceeding half the length of the ramus ; dorsal seta small, but 

 distinct. 



Male (fig. 3) a little smaller than female, and having the shell 

 somewhat less vaidted dorsally. Prehensile palps of posterior 

 maxillfe (figs. 7, 8), as usual, somewdiat unequal on left and right 

 sides, and apparently differing a little in shape from those in the 

 type species. 



Length of shell $ 0-91 mm., height 0-42 mm., width 0-30 mm. 



Remarks. — This form is closely allied to the type species, 

 exhibiting a very similar shape of the shell. It is, however, of 

 considerably larger size, and moreover diffei's in the less com- 

 pressed shell and in the moi'e I'obust and quite smooth caudal 

 claws. Nor is there any trace of the fine denticles found in 

 P. temiis on the dactjdus of the anterior legs. 



* Tliio]. Jabibiu-her, .vol. xxi. pt. 4, p. 404, ijil. xx. jfigs. 173-18/3. 



Proc. Zuol. Soc— 1910, No. XLVIII. 48 



