750 I'ltdF. a. (). sAus ox [May 3, 



Ofiius 4. 8ti:xo( YPius C 0. Siirs. 



Kemarhs. — The type »>t' tliis licmis is ,S'. nialcohnsoiii l^rady, of 

 wliicli a (Iftailed (leM-ription lisis been ^iven by tlie present autlior 

 from Australian specimens. The most prominent character dis- 

 tingnisliing: this genus is un(:pu'sti<)n;il)]y the peculiar asymmetry 

 of the caudal i-ami, the right one of which is nnich coarser than 

 the left and armed along the dorsal edge witli a comb-like series of 

 strong denticles, wanting or only slightly indicated on the left ramus. 

 This chai-acter is found in several other species lecently described 

 by Dr. Yavra and Dr, Midler, and may thus j^rove to be a very 

 good generic ciiterion. The foi-m recorded b}' the pi-esent author 

 as Stetion/pris chevrenxL in which such an asynnnetry does not 

 exist, I am now inclined to lefer to the genus IFerpetocypris, in 

 spite of the presence in this form of distinct, though very short 

 n;»tatoi'y seta^ on the inferior ai)tenna\ In all other characters 

 this form exhibits a much closer relationship to the genus 

 Hcrpetocjipris than to Stenocypris. A genuine species of the 

 present genus is desci'ibed below. 



25. SxEXOcYnas PERARMATA lirady. (Plate LXXII. figs. 8 10.) 



StenQCjipris perannata Brady, Entomosti-aca collected in Natal 

 by Mr. J. Clibson, Proc. Zool. Soc. Lond. 1904, vol. ii. p. 126, 

 pi. viii. figs. 50-57. 



Specific Characters. — Fejialv:. Shell much compressed ; seen 

 laterally (fig. 8) of elongated silifjuose shape, greatest height 

 occurring behind the middle and only slightly exceeding one-third 

 of the length ; anterior extremity somewhat obliquely I'ounded, 

 posterior narrower and obtuse at the end, none of the extremities 

 defiexed ; doi-sal mai'gin gently curved, sloping evenly towards the 

 anterior extremity, more steeply towanls the postei'ior, above 

 Avhich tiiero is trace of a slight concavity; vential margin ex- 

 hibiting in front of the middle a slight sinus bounded anteriorly 

 (in the oral region) by a small convexity : seen dorsally (fig. 9) 

 narrow oblong in forin. with the greatest Avidth only slightly 

 exceeding one-quartt r of the length, both extremities acuminate. 

 Valves thin and pellucid, only slightly unequal, the left over- 

 la|)ping a little the right along the anterior extremity and also 

 somewhat iiehind. Surface of shell smooth, but rather densely 

 hairy both at the extremities and below. Caudal lami (fig. 10) 

 exhibiting the structure characteristic of the genus ; right ramus 

 conspicuously broader than the left and armed on the distal part 

 of the dorsal vi]ij^k:' with a row of about eight coarse teeth, followed 

 liva nund)erof smaller and somewhat une(|ual dentichs; dorsal edge 

 of left lamus with only very small hair-like denticles in its outer- 

 most part; apical daws of both rami rather strong and somewhat 

 uneipial, the distal one being much the longej-, though .scarcely 

 exceeding half the length of the ramus ; both claws coarsely 

 denticulated along the greater part of the concave edge, seta of 



