38 CRETACEOUS PELECYPODA 



9^^ lihlnoiiii/a, A. Adams, 18G1, (Ann. and Mag. Nat. Hist., vol. xiii, p. 207). 

 This A\'as proposed as a sub-genus for such f(n'ms as have the surface of the 

 shells lamellar, like Necera proper, but possess a small triangular cartilage-pit, and 

 two lateral teeth in the right valve. — JV. (Rli.J Philqnnensis, Hinds. 



9&. Cardiomija, A. Adams, 18G1, (ibid, p. 208) ought ap])areiitly to include 

 the species of Ncccra which have the siu-faee radially ribbed, like N. Gouldianu of 

 }liuds. 



H. and A. Adams, in their work on the genera of Mollusca (ii, p. 309,) class 

 Theora next to Naera, apparently following the suggestions of Hinds regarding 

 the relation of these two genera, Hinds having first described a few species of 

 Theora under the generic name of Necera. I have examined the animal of some 

 species of Theora, Avhich chiefly live in brackish water along the coast of the Bay 

 of Bengal, and found them to be allied to those of the Scrobicvlariid/E, to Avhich 

 family the genus must be referred. On account of a very marked relation of the 

 fossil Palceomya to Theora, I shall treat of the former also in the last named family, 

 and the same applies to a peculiar recent shell called Tleclodon by Carpenter. 



10. Tororaija, Forbes, 18i4. Shell oval, equivalve, ventricose, gaping poste- 

 riorly, covered with a scabrous epidermis, below which the surface is either punc- 

 tated, or granular, or finely spinulous, the unevenness of the surface appearing to 

 give firm attachment to the epidermis. Hinge with a strong tooth in the left valve, 

 and two smaller ones in the right, and in each with a posterior groove, in which 

 is lodged a small cartilage ; fulcra prominent for the attachment of a more or less 

 strong ligament ; pallial line submarginal, and posterior sinus small. 



Deshayes (Paris fossils, 2nd edit., p. 21-8,) correctly,* I think, suggests, that 

 the fossil shells w-hich Sowerby called Thetis, and which name has been adopted by 

 II. and A. Adams in preference to that of Forbes, are thoroughly distinct from 

 those belonging to the present genus. Of the former I shall treat in the Venerid^ 

 (sub-family dosiniinje). 



The first Foromyce as yet known are only from eretaceoiis rocks, thougli very 

 little doubt exists that the genus is much older. Of recent shells there are not much 

 more than about half a dozen species known (see A. Adams in Ann. Mag. Nat. 

 Hist., xiii, 1864) ; they are deep water shells, and have been found in European and 

 Chinese seas. The form of the siphons and of the foot, equally A^ith that of the shell 

 and its hinge, necessitate, as already pointed out, the classification of this genus in 

 the coRBVLiNJE, in prefei'ence to that in the anatisis^. Foromya is not identical 

 Avith ^«c/««m, Recluz, but Emhla Korcnii of Loven is identified by Sars, and 

 by other very able observers of the North-European marine fauna, Avith the type 

 species Foromya granulata, N y s t. Gray formerly placed Emhla (as distinct from 

 Foromya) in the Lasseiv^, 



11. Azara, d'Orbigny, 1839. Shell like Corhnla, right vah-e with tAA'o obscure 

 toctli, sei)arated by a broad pit, in Avliich fits the process of the left A'alve supporting 



* Sul)s('queiitl.v (ibid. p. 408) he iilludes to tlie f;reiit siinilurit)- of Soworby's Thetis ^\A Purumi,a, but I Jo 

 not think that this statcmcut has moii.' wi'ijrht than thu Ibnuer. 



