57() MR. G. S. BRADY'S MONOGRAPH OF 



half the length. Extremities rounded and nearly equal, the anterior slightly narrowed. 

 Ventral marrin straight or slightly convex, dorsal arched, somewhat angular in the 



e 1 " «"»"o 



End 



middle, where it is highest. The outline, as seen from above, is oval, tumid ; width equal 

 fco half the length; extremities rounded and nearly equal; hinge-margins depressed pos- 

 teriorly so as to form a longitudinal sulcus behind the centre of the carapace. 

 i rci ilar. The surface is quite smooth and polished; colour sea-green, faintly mottled 

 with patches of a deeper hue. 



Length ^ * n -> height -^ in. 



Oyprii trigonella was found by the Rev. A. M. Norman amongst some freshwater 

 .hells collected by the late Mr. Barlee. Erom the character of the Mollusca with 

 which it was associated {Planorbis spirorbis and Limncea peregra) we may presume that 

 it was taken probably in the south of England. The gathering contained several 

 specimens of this Cypris, all of them agreeing in size and general character. 



14. Cypris reptans (Baird.) (Plate XXV. figs. 10-14, and Plate XXXVI. fig. 4.) 



Nat 



tab. xix. fi^s. 3, 3a; Jones, Tert. Entom. p. 16, pi. i. figs. 7a-7e. 

 Cyprii reptans, Lilljeborg, Dc Crustaceis, p. 123, tab. xi. figs. 21-23, tab. xii. figs. 7-9. 



Trans 



Nat. Field Club, vol. vi. p. 106, pi. iii. figs. 1-5. 



Valves oblong, subreniform, compressed, unequal, the left being considerably the 

 larger. The anterior and posterior margins are obliquely rounded, somewhat angular 

 1 >elow, and nearly equal in height, the posterior somewhat the higher. Ventral border 

 -lightly sinuated, dorsal straight or very slightly arched. Seen from above, the carapace 

 is compressed, oblong-ovate, widest in the middle, the anterior extremity pointed. End 

 view ovate, prominently keeled in front and below. The surface is smooth and shining, 

 and bears a few scattered hairs. Colour greenish with patches of lighter and darker 

 hue, sometimes banded with orange or brown. The limbs and their terminal claws are 

 all long and slender. Seta? of the lower antenna? short and rigid, sometimes slightly 

 plumose, but mostly quite simple ; the principal bundle rises from the apex of the second 

 joint, and consists of four long and one short seta; an auxiliary brush springs from the 

 middle of the joint, two on the outer, and one on the inner side : none of the setae reach 

 as far as the apices of the terminal claws. The postabdominal rami are long, Blender, 



and serrated on the internal border ; the two larger terminal claws are also serrated in a 



similar manner. 



Length ^ in., height -fc in. 



A very common species, and (excepting C. Uspinosa) the largest of all the British 

 freshwater Ostracoda. It often occurs in very great abundance, especially in the 



"cooling-ponds" of collieries, &c, where the temperature of the water is higher than 

 ordinary. 



In external appearance, and in habits of life, this species bears much more resem- 



blance to the Condon* than to the true Cuprides ; but the structure of the lew 



