CYPRELLA. 



39 



in profile, the breast more retreating, and the rings fewer in number, and investing only 

 the hinder half of the valve. This is our Var. subannulata (C. subamiulata, Jones, 1870). 



In fig. 11 we see a similar shell, dark grey, from Little Island, Cork (Mr. J. Wright, 

 F.G.S.), rather more convex than the last, with a somewhat stronger tubercle, and 

 marked by a few more rings on its posterior moiety. This has the definitely apiculate 

 and indented posterior margin that we see in M. De Koninck's fig. 6 c. 



Fig. 16 and fig. 10 agree in the symmetrically elliptical shape of the hinder 

 extremity, whilst fig. 11 is indented and apiculate posteriorly, like De Koninck's original 

 specimen (his fig. 6 c) ; but figs. 11 and 10 agree as to the form of the beak or hood, 

 and fig. 16 diSers in that point from all. So also figs. 10 and 16 agree as to general 

 convexity with each other, and with all the Belgian specimens, and their tubercles are 

 low; whilst fig. 11 has an unusual convexity of the hinder half, and its tubercle also is 

 strong. We see an extra large tubercle in fig. 15, but this cast (Belgian) is not well 

 preserved ; and the tubercle is very feeble in fig. 18, also a Belgian cast (compressed). 



Looking at all the slight differences above detailed, and weighing them against the 

 features of mutual resemblance, we must still regard all these specimens as belonging to 

 one species; suggesting, however, that fig. 10 (from Settle) and fig. 11 (Cork) are 

 varietal (Var. subannulata), if not male or young specimens, and that possibly fig. 16 may 

 also be a local variety. 



Length. 



De Koninck's figs. 6 a — e • - ■ W 

 Fig. 10, from Settle (Var.) . . . -i^ 

 Fig. 11, from Cork (Var.) . , . \ 

 Fig. 14, poor cast, Belgium . . f 

 Fig, 16, from Settle . . . . \ 

 Fig. 18, compressed cast,^ Belgium \ 



Cyprella chrysalidea is represented in Prof. De Koninck's plate 52 by the right 

 valve (fig. 6 c) with its front upwards, by the dorsal {e) and ventral (a) views of the 

 carapace, and by two views of natural size {h and d). It appears to us that the artist 

 made too strong a line and too free a curve between the hood and the tubercle, as also 

 in fig. 7 « of the same plate. The curve in fig. 3 we interpret somewhat differently. 

 See further on, p. 40. 



C. chrysalidea is stated by De Koninck to be ten millimetres in length, and to 

 be very rare at Vise ; so also M. E. Dupont refers to it as being very rare in French 

 Hainault ('Bull. Acad. Belg.,' ser. 2e, vol. xv, p. 110). M. Bosquet has kindly sent us 

 some Belgian casts of this interesting little fossil. 



^ This has been somewhat compressed ; hence a greater height anil less thickness, perhaps, than in 

 the original carapace. 



Height. 



1 



■1 



1 



8 



JL 

 7 



JL 

 6 

 \ 

 6 

 1 



Thickness. 



\ inch. 



\_ 



9 

 J, 

 8 

 J_ 

 7 

 \ 

 9 

 \ 

 9 



Proportions. 

 Lena-th. Heig-ht. Thickness. 



11 



10 



11 



14 

 12 



15 



6 : 4. 



6 : 5. 



7 : 6. 



8 : 7. 



