340 ME. ROBERT GURNEY ON 



specimens wliich can be referred to that species. On the other 

 hand, the shape of the shell (fig. 16) points unmistakably to the 

 closely allied species C. aldabrce, with which my specimens agree 

 also in other respects. Unfortunately I have not been able to 

 find a single male, so that the comparison is incomplete. 



ONCOCyPRIS PUSTULOSA, sp. n, (PI. III. figs. 17-21.) 



Seen froin above the animal is pear-shaped, very broad behind 

 and tapering anteriorly, with a constriction in front of the eye 

 (fig. 17). In quite young individuals the shape is that of an 

 Qg^.1 with the gi'eatest width just behind the middle and tapering 

 evenly in front and behind. Seen from the side the two valves 

 are alike, kidney- shaped, broader in front than behind (fig. 18). 

 The cuticular border is broad a,nteriorly, scarcely visible ventrally, 

 and narrow beliind. Seen from inside, the structure of the shell 

 is distinctive. In the left valve the anterior cuticulai- bolder is 

 very broad and springs from the edge of the shell, its point of 

 origin being marked by the accompa.nying setae. Beyond this 

 point is the " pore-canal " zone, in which are seen a series of 

 strongly marked semicircular loops which appear to indicate 

 unbranched pore-canals, but their real nature is not at all clear 

 (fig. 19). Cutting across them is seen a conspicuous ridge. The 

 structure is much the same posteriorly and in the right shell. 



The surface of the shell is thickly covered with little knobs, 

 but in very young specimens it is strongly reticulated and pitted. 

 The eyes are very large and united. The general colour, in 

 spirit, is golden yellow with a conspicuous greenish pigment- 

 spot on either side of the eye. 



The maxilla has no respiratory plate, but in 2:)lace of it there 

 is a single small seta. Miiller gives the entire absence of setfe as 

 an important character of the genus, and it is possible that the 

 specimen in which I have seen the seta is abnormal in this 

 respect. From the small number of specimens at my disposal 

 I am unable to go further into the matter. In the second 

 maxilla there are two strong spines on the third lobe, one of 

 which is toothed and the other smooth. In the fii'st leg the 

 third and fourth joints are fused ; the last joint bears a very 

 large curved spine and a single short seta (fig. 20). The second 

 leg has a well-developed terminal joint bearing a long curved 

 claw, a seta of about the same length, and a small hair (fig. 21). 

 The furca is a simple flagellum. 



Length -S-'SS mm. ; width '43- 54 mm. ; height •3-*38 mm. 



A very few female specimens of this species were taken in a 

 tank by Lady Horton's Drive at Kandy. The genus Oncocypris 

 was established by G. W. Miiller for a species, 0. vodtzkowi, from 

 Madagascar, which has since been found also in Abyssinia (Daday) 

 and South Africa (Brady). The only other species of the genus 

 is 0. costata Daday from German East Africa. It is therefore of 

 considerable interest to find that a species of this Afiican genus 

 occurs also in Ceylon. 



