26 Trof. T. Rupert Jones — Canadian Ostracoda. 



of them (apparently a right valve) retains all its outline except the 

 antero-ventral curve. The edges have been divested of their special 

 characters by the loss of substance. 



Valve broad-oblong, with the dorsal and ventral margins nearly 

 straight and parallel ; hinge-line distinct but not the method of 

 hingement; semicircular posteriorly, and obliquely rounded (broken) 

 anteriorly. 



Such subquadrate carapaces occur among species of Cythere, 

 Cytheridea, and LoxoconcJia : as Cythere fusca, C. Jurinei, G. lutea, 

 and Loxoconche pusilla. In the " Proceed. Bath Nat. Hist. Antiq. 

 Field Club," vol. vi. 1868, pi. i. fig. 6, shows such an oblong Cythere, 

 and fi^gs. 5, 7, and 8 some Cytheridea of similar shape, all from the 

 Fuller's-earth Oolite. 



The absence of characteristic features beside the mere outline 

 precludes a definite determination beyond the fact that the species 

 may be assigned to the marine genus Cythere. 



This specimen of two valves occurs on the same piece of limestone 

 ■with Fig. 7. 



Candona, Baird, 184:5. 



7. Candona (?) Sanct^-Mari^, sp. nov. PI. 11. Figs. 7a, h, c. 



Length 1-84, height "92, thickness -8 mm. 



Suboblong and irregularly elliptical ; semicircular in front, 

 narrower and obliquely rounded behind ; ventral edge slightly 

 convex, dorsal partly straight (on the hinge-line), rapidly curving 

 in front, and curved with a gentler slope behind, making a narrow 

 and almost subacute oblique posterior margin. Surface smooth and 

 uniformly convex, but more gently sloping in the dorsal than in 

 the ventral region (Fig. 7c). 



Two specimens in greyish-brown limestone of the nodular layer, 

 with small molluscs like Faludina, Planorbis, etc. From the North 

 Branch of the Milk River. 



This form of carapace-valve is rare among the Ostracoda generally, 

 but there is an approach to it in Cythere sometimes (as in C. teres. 

 Trans. E. Dublin Soc, n.s. vol. iv. p. 133, pi. xiv. figs. 36, 37) ; also 

 occasionally in Krithe, but from this it differs posteriorly. Its 

 nearest figured representative is the freshwater Candona lactea as 

 shown in the Trans. Linn. Soc. vol. xxv. pi. xxiv. figs. 54^58. 



Cytherella, Bosquet, 1852. 

 8. Cytherella cruoifera, sp. nov. PL II. Figs. 8a, b, c. 



Length l'7o, height 1"2, thickness 1"04 mm. 



Valve obtusely suboval ; ends almost equal ; one edge less fully 

 curved than the other ; uniformly convex, smooth, and marked with 

 a small, round, central depression, which is divided into four little 

 triangular spaces by a very slightly raised, whitish, cruciform line. 



Unfortunately we cannot judge of the marginal characters of 

 this specimen. The oval and smooth aspect suggests the marine 

 CythereJla for the genus ; and the full convexity is not inimical to 



