BIVALVIA. 159 



If this diagnosis be adhered to, it is obvious that the living shell {Mactra triangularis) 

 which M. Deshayes has taken for the type of the new genus Goodallia must be discarded 

 from it, as it has a strongly denticulated margin. 



Goodallia of Turton has by general assent been suppressed as untenable, and the 

 resuscitation of the name by M. Deshayes will be at the expense of some confusion. 

 If that name be admitted, it must stand upon its own merits wholly irrespective of 

 Turton or of the triangidaris, and upon the reversion of the dental formula. Should that 

 be constant, it may be considered a generic distinction ; and in these older Tertiary shells 

 of M. Deshayes, as well as the shell under consideration, there appears to be an absence 

 of the lateral tooth which is present in all the small species of true Astarte. 



These shells of M. Deshayes seem to be the only representatives of om* present genus 

 in the Paris Basin. 



WOODIA. Deshayes, 1858. 



Generic Character. " Testa suhrotunda, cequivalvis, aquilateralis, clausa, IcBvigata vel 

 excentrice striata ; marginibus oblique crenidatis. Cardo crassiusculus, in valvula dextra 

 unidentatus ; dente wagno, triangulari, mediano ; in medio subcanaliculatus, in valvula 

 sinistra bidentatus ; dentibus inaqualibus divaricatis ; aliquantisper dentibus lateralibus 

 obsoletis. Ngmpha minimce depressa, ligamentum minimum externum ferentes. Cicatri- 

 cul(E muscular es minima, aquales, ovatce vel subrotundce. Linea pallealis simplex!^ — 

 Deshayes. 



M. Deshayes has proposed the above name as generic for the reception of some 

 species of shells of which he considers Tellina digitaria, Linn., to be the type. In my 

 Monograph of the Crag Mollusca this shell is described under the name of Astarte, as 

 I thought it merely an aberrant form of that genus ; and although I feel complimented 

 by the intention of that able conchologist, I am not now convinced that the differences 

 between it and Astarte are sufficient to constitute a generic separation. I thought it 

 possible that, when the animal of the Mediterranean shell became known, it might 

 present some peculiar distinction ; but I doubted whether the shell itself would justify 

 a generic removal. 



There are three species from the Paris Basin, figured by M. Deshayes under the above 

 generic name, which cannot fairly be included in the genus Astarte, and also one from our 

 English Lower Tertiaries, for which I have been obliged to adopt the name of Woodia. 

 These older Tertiary fossils not only differ from the genus Astarte, but they appear to 

 me to differ from the generic character pertaining to Tellina digitaria, Linn. In this 

 latter shell the connector is placed wholly upon the exterior on a prominent fulcrum ; but 

 in the present fossils from the older Tertiaries the ligament is situated in a linear de- 

 pression within the dorsal margin, although it probably acted in a ligaraental manner over 



