ANIMALS. 119 



Terebratula Schlotheimi, Von Buck. Tennant, Strat. List, p. 88, 1847. 

 Camarophokia — „ King, Catalogue, p. 7, 1848. 



Terebratula — „ Howse, Trans., T.N. F.C., vol. i, p. 252, 1848. 



— — „ Geinitz, Versteinerungen, p. 12, pi. iv, figs. 



43-50, 1848. 



Diagnosis. — The typical Camarophoria. Generally as wide as long ; rarely exceeding 

 five eighths of an inch in length or width ; smooth ; plain, and somewhat tumid in its 

 posterior half ; plicated or ribbed, and deeply sinuated in its anterior half ; with from 

 one to six generally dichotomous ribs in the sinus, or on its corresponding elevation, and 

 the same varying number on the sides ; of a sub-pentagonal form ; pointed behind ; 

 and rounded in front. Large valve rather rounded in the umbonal region ; depressed 

 at the sides ; and with the front or sinus portion considerably produced arcuately 

 beyond, and falling below, the latter (considering this valve as the upper one) ; fissure 

 small. Small valve with the median elevation high in front, and the sides rapidly 

 sloping. Marginal expansions extending to about half the length of the shell. 



Camarophoria Schlotheimi is a variable species, — not so much in its form as in the 

 number of its ribs. Occasionally it is very much tapered behind', and longer than wide ; 

 whereas the general tendency is to the contrary. As regards variation in the number 

 of its ribs, there are five or six well-marked forms depending on their number 

 in the sinus : the ribs on the sides are also subject to the same variation : occasionally 

 specimens occur without any ribs either in the sinus or on the sides, as exhibited 

 in fig. 10, PI. VII. I suspect that Dr. Geinitz has identified a shell belonging to the 

 latter variety with the Camarophoria superstes of De Verneuil. I am also led to 

 suspect that the shell which is identified in the ' Versteinerungen' with the Terebratula 

 Geinitziana of the same author is a numerously plicated form of the present species. 

 The principal varieties have been very truthfully represented by Mr, G. B. Sowerby, jun., 

 in PI. VII. With the exception of some slightly prominent lines of growth and a few obso- 

 lete longitudinal strise, the surface of this species is remarkably smooth. The marginal 

 expansions are slightly ribbed, the ribs being a continuation of those on the valves. 



Catnarophoria Schlotheimi closely resembles the C. crumena^ of Martin, which 



1 When examining, in the Autumn of 1848, Mr. J. de C. Sowerby's valuable collection of fossil shells 

 figured in tbe ' Mineral Conchology,' I was highly gratified with discovering that the shell represented in 

 plate Ixxxiii, fig. 3, and identified with the Conchyliolithus Anomites {Crumena) of Martin, belonged to the 

 genus Camaraphoria. The specimen which originally belonged to Mr. Martin, resembles the one figured 

 in the ' Petrefacta Derbiensia' (pi. xxxvi, fig. 4) so closely as to allow of little doubt existing of its being the 

 original of the figure just cited. The others pecimens represented in the ' Mineral Conchology,' pi. Ixxxiii, 

 figs. 2, 2*, belong to a very difi'erent species, and evidently to the genus Hypothyris. The Gilbertsonian 

 collection in the British Museum contains a card labelled Terebratula plicatella, Dalman, and mounting 

 nine specimens with from three to five ribs in the sinus : no locality is given : they are undoubtedly 

 Camarophorias : my notes state that they are identical with C. Schlotheimi; but I now suspect them to be 

 the same species as the one noticed in the text, found in Weardale, Durham. I have also a memorandum 

 stating that C. crumena occurs in the same collection. 



