9.] ON SOME FRESHWATER OSTRACODA AND COPEPODA. 29 



Cypris malcolmsonii, Brady, L c. Linn. Soc. Journ. Zool. Vol. 

 XIX, p. 297, PI. XXXVIII, figs 5-7. 



Specif c Characters. — Shell seen laterally elongated reni- 

 form, height about equalling 2 / 5 of the length, both extremities 

 rounded, dorsal margin flattened, nearly straight in the middle, 

 ventral deeply sinuated: seen from above very narrow oblong, 

 greatest width not attaining l f% of the length, sides flattened, 

 both extremities subacuminate. Surface of shell smooth beset 

 with scattered hairs. Valves nearly equal, the left only very 

 slightly overlapping the left, free edges strongly chitinised. with- 

 out any pellucid border, but transversally ridged, the ridges 

 being of greatest length at the upper part of the anterior 

 extremity. Colour light greenish with indistinct yellowish shades, 

 coecal appendages of intestine yellowish green, ova contained 

 in the body bright reddish. Eye very large and conspicuous. 

 Caudal rami very unequal, the right rather broad, slightly 

 curved, scarcely tapering, outer part of dorsal edge elegantly 

 pectinated, left considerably narrower, without distinct teeth of 

 the dorsal edge; terminal claw about twice as long as the other, 

 both coarsely denticulate ; apical seta almost as long as the claw, 

 seta of dorsal edge absent. Length of adult female 1,70 mm. 



Remarks. — This beautiful species is undoubtedly identical 

 with the form described by Baird from Nagpur, India, under 

 the name of Cypris cylindrica Sowb., and more especially agrees 

 with the figures given of his variety „major\ Mr. Brady, who 

 had for examination specimens of the same species from Ceylon, 

 does not however agree with Baird in identifying this species 

 with the fossil form described by Sowerby, and hence has 

 proposed a new specific denomination, that of malcolmsonii. Whether 

 the two varieties named by Baird belong to the same species, 

 I am unable to say. Baird has found both to be exactly similar, 

 except in size, the variety „major tt being ascertained to be 

 about twice as large as the other variety, in spite of the latter 

 being full-grown. 



Description. — The shell of adult specimens attains a length 

 of about 1,70 mm, which would seem nearly to correspond with 



