OF SOUTHERN INDIA. 265 



5. TelUmya, Brown, 1827. Shell oval, inequilateral, concentrically striated, 

 hiDge as in Montacuta, but the cartilage partially hardens to a solid ossicle; type, 

 T. Udentata, Mont. 



H. and A. Adams restrict the ^^'m^MontacutaioM.o^i^.^v^^Ligulasiihstriata, 

 referring to certain differences in the organisation of the animal of this species 

 as compared with Montagu's Mya bidentata. Prom the descriptions Jeffreys 

 gives in his Brit. Conchology there seems to be, however, no essential difference 

 between the animals of both, and that author consequently places them both in 

 Montacuta, It certainly appears that the anterior expansion observed on the 

 foot of M. substriata is not a constant form of it ; but as the two species referred 

 by H. and A. Adams to TelUmya (T. bidentata and ferriiginosaj differ from 

 the former by the want of radiating lines, and that of an ossicle, and also by their 

 habitat, they may be kept separate. 



6. Kelliella, Sars, 1868. This name occurs in the list of northern deep 

 sea shells, published by Sars, and translated in Ann. Mag. Nat. Hist., 4th ser., 

 vol. iii, p. 429. I am not aware that the characters have as yet been pointed out. 

 The type species, K. abyssicola, Sars, is placed between Astarte and Montacuta, 



7. Lascea, Leach, 1827, fForonia, Eecluz, 1843). Shell oblong or roundish, 

 usually somewhat inflated, very thin, concentrically finely striated; hinge with 

 two large diverging cardinal teeth, and in the left valve with an additional minute 

 hook-like tooth between the two ; cartilage on a raised groove on the shorter side 

 of the shell; type, Cardium rubrum, Mont. Brown having proposed in 1827 the 

 name Zascsa for the well known species of Montagu, and having used the same 

 again in 1833 as a generic determination for the same species, the genus must be 

 adopted in preference to Becluz' Poronia. 



It seems probable that this genus is largely represented in a fossil state, and 

 that a number of the Corbul(B with thin shells will have to be referred to it. 



8. Lepton, Turton, 1822. Shell oval or sub-orbicular, slightly gaping at 

 both ends, smooth or scrobiculate on the surface; hinge with two very widely 

 diverging and elongated laminar teeth, between which there is sometimes one 

 small cardinal tooth in the right and one or two in the left valve ; but sometimes 

 these small teeth are obsolete ; cartilage situated in a groove in front of the pos- 

 terior large tooth. Type, Lept, squamosum, Mont., sp. The hinge of Lepton is, 

 as Deshayes remarks, quite similar to that of Erycina, except that the outer 

 laminar teeth are larger and the shell thinner; the animals of both differ greatly 

 by the prolongation of the anterior and posterior tube in the first named genus, 

 and also by the disc-like foot. 



9. Fristlphora, Carp., 1866, (Proc. Calif. Acad., p. 210). Shell oval, with 

 two diverging teeth in each valve, the anterior being conspicuously shorter than 

 the posterior, sulcated near the beaks, ligament situated in a groove between them ; 

 type, P. oblonga, Carp., from San Diego, 



10. JBornia, Philippi, 1836, (Enum. Moll. Sicil., i, p. 13). Shell elongately 

 oval, with slightly projecting beaks, almost equilateral, surface finely concentrically 



