1449 



Section Corbicula s. s. Type C. fiuminalis (Miiller), 

 Characters as above. Not viviparous ? 



Section Veloritina Meek, 1872. Type C. Durkeei Meek. Bear River 

 Cretaceous of Wyoming. 



Shell thick and solid, gibbous trigonal, the lunular and ligamentary areas 

 deeply depressed ; hinge with the cardinals as in Cyrena s. s., the left posterior 

 cardinal obsolete in the adult ; left posterior lateral formed by the bevelled edge 

 of the valve, long, coarsely striated ; anterior laterals short, adjacent, feebly 



striated ; pallial line feebly flexuous. 



* 



Section Corbicnlina Dall, 1903. Type Corbicula Angasi Prime, Journ. 

 de Conchyl., xii., p. 151, pi. vii., fig. 6, 1864. Murray River, 

 Australia. 



Shell small, thin, elongate-oval, finely concentrically sulcate ; nymphs short, 

 their opposing surfaces granulate ; hinge-teeth thin and delicate, laterals long, 

 subequal, crenate; cardinals very oblique, otherwise as in Corbicula; pallial 

 line entire. 



This group has numerous species in India, Java, Madagascar, and Aus- 

 tralia. C. sikaroe Ancey, from Madagascar, is viviparous, and the other species 

 may be so. 



Section Tellinocyclas Dall, 1903. Type Cyrena tellinella Deshayes, 

 Coq. fos. bas. Paris., i., p. 123, pi. xix., figs- 18-19, 1824. Lower 

 Eocene. 



Shell small, solid, thick, inequilateral, the anterior end shorter, with low 

 beaks, the valves narrow and elongate; the hinge as in Corbicula but the 

 laterals straight and shorter, especially the anterior ones; the pallial line is 

 entire, without flexuosity of any kind. 



The shell figured by Sandberger under this name shows only two cardinal 

 teeth in the right valve and a decided flexuosity in the pallial line and is re- 

 ferred by him to Loxoptychodon. The shell figured by Deshayes under the 

 name of Cyrena singularis is externally similar but has a well-marked, rounded 

 pallial sinus. The specimen before me has three cardinal teeth in each valve 

 and a perfectly regular entire pallial line. Which is the C. tellinella of Ferus- 

 sac I am unable to determine, but the shell under observation appears to be 

 that figured by Deshayes, and, owing to its remarkable form in such strong 

 contrast to any other Corbicula, seems entitled to sectional rank. 



