SULCUNA; CYPRELLA. 37 



2. SuLCUNA cuNicuLUS. Sp. iiov. Plate IV, figs; 5 a, b, c ; 8 a, b, c. 



Smaller than S. lepus, and, in one specimen at least, more convex, strongly notched 

 and hooded anteriorly (in a well-preserved specimen, fig. 8), and far more strongly 

 indented by the dorsal furrow, whereby the antero-dorsal region of each valve is divided 

 ofi" as a pointed process, tending backwards and outwards. This curious species has a 

 distant resemblance in outline to a couchant rabbit, with distinct pointed ears. In the 

 end-view, fig. 8 b, these processes diverge more than in fig. 5 b. In fig. 5 a the anterior 

 margin, its dorsal angle being obscured by matrix, is not perfectly shown, and a 

 little tubercle, which is merely a local irregularity of the convex surface, is figured too 

 strongly. 



Fig. 5. Length \; height ^ ; thickness -j^. Proportions 9:6:3. 



Fig. 8. „ ^; „ \; „ i „ 10:7:5. 



Mr. J. Wright, P.G.S., has found well-preserved but rather rare specimens in the 

 Carboniferous Limestone of Little Island, Cork. 



VI. CYPRELLA, Be Koninch. 



Cyprella et CYPRiDiNA, De Koninck^ 1841, 1844. 

 Ctprella, Dupont, 1863. 



— Jones and Kir kby, 1863. 



The generic characters of this peculiar form are best understood from the description 

 of the two species known to us. The general form is that of Cypridinella and Cypri- 

 dellina, with apiculate and indented end and a truncate front; the latter notched, sloping 

 downwards, and with either a nearly vertical or a receding antero-ventral margin. There are 

 also present tubercle and dorsal sulcus, of varying intensities ; but the chief character is a 

 vertical and necessarily annular striation, farrowing, or step-like marking on the carapace. 

 These parallel lines are more distinct, wider apart, and more step-like in Cyprella 

 chrysalidea than in C. annulata. C. chrysalidea also has a more hood- like construction 

 of the antero-dorsal region, over the sinus and notch, than either its fellow species, or 

 any of the Cypridinads we know of. None of our figures, some of the best of our speci- 

 mens being crushed casts, express quite so much as we can see in them ; and M. De 



^ M. Cantraine, in reporting, together with M. Dumont, on Prof. De Koninck's " Memoir on the 

 Carboniferous Crustacea of Belgium," in 'Bullet. Acad. Belg.,' viii, partie l^re, p. 801 (1841), expressed 

 the opinion that Cyprella might be Cijpridina, and that Cyprella chrysalidea, De Kon., and Cypridina 

 annulata, De Kon., might belong to one genus. In the latter opinion we fully coincide. 



