162 PKOCEEDINGS OF THE MALACOLOGICAL SOCIETY. 



being quadrangular or trapezoidal, with opposed subcentral umbones. 

 M. Cossmann summed up its characters in the following terms : " The 

 hinge is almost identical with that of Dosinia, but the short, open, 

 rounded sinus is rather that of some Tivelina. By its shape one would 

 take this shell for a species of the family Cardiidse, but from that it is 

 completely separated by its sinus and its hinge " (op. cit., p. 128). 



With regard to the hinge, as shown in M. Cossmann's figure, 

 I cannot see that it has any special resemblance to that of Dosinia ; ^ 

 still less can I see any likeness between its dentition and that of 

 Tivela, near which Fischer placed it,* being apparently under the 

 erroneous impression that there were two posterior cardinals instead 

 of a single bifi.d one. The general arrangement of the teeth is similar 

 to that of Callista and Tivelina, the anterior and median cardinals 

 being close and nearly parallel, while the posterior is divergent and 

 bifid ; the somewhat different look of the hinge being really due to 

 the shortening of the hinge-plate as a consequence of the peculiar 

 shape of the shell. The short pallial sinus also resembles that of 

 Tivelina, and is very different from the forms of sinus found in the 

 genus Dosinia. 



So far, therefore, as it is possible to form an opinion from the 

 characters of a single valve and from a figure only, Dollfusia seems 

 to me more closelj'' related to Tivelina than to any other group of 

 Veneridae, and it may especially be compared with T. splienarium. 



9. Circe, Schumacher. 



No shells referable to the typical group of the genus Circe have yet 

 been found either in Cretaceous or Eocene deposits, those from the 

 Gosau Beds which were described by Zittel in 1864 as Circe having 

 since been transferred to Cyprimeria, while the shells referred to Circe 

 bj^ M. Cossmann in 1886 belong to its subgenera. 



In the Oligocene, however, there is a shell which certainly seems to 

 belong to the typical section of the genus, as exemplified by C. Utterata, 

 Linn. This was described as Cyth. varialilis by Stan. Meunier in 1880,^ 

 and^was recognized as a Circe by M. Cossmann* in 1891. It is found 

 at Etampes, south of Paris. The shell varies considerably in shape, 

 from bl'oadly oval to suborbicular. The external surface is con- 

 centrically grooved. The hinge exhibits the characteristic three 

 straight and slightly divergent cardinal teeth of Circe proper, the 

 anterior one being vertical and the other two oblique. The pallial 

 line is slightlj' sinuated. 



Of the four Eocene species referred to this genus in 1886 by 

 M. Cossmann (op. cit., p. 126), C. vetula, Desh., and C. GoodalUoides, 

 Cossm., seem to belong to the section Circenita of Jousseaume, which 



^ Having written to M. Cossmann on this point, I am glad to find that he does not 



now maintain its affinity with Dosinia. 

 2 Manuel de Conchyliologie, 1887, p. 1079. 

 •' Nouv. Arch, du Museum, ser. ii, p. 242, pi. xiii, figs. 15, 16. 

 * " Eevue de la faune du terr. Olig. d'Etampes " : Journ. de Conch., 1891, p. 274. 



