80 CEETACEOUS PELECYPODA 



whether the shell is perfectly equivalve, for in many instances I fonnd the beaks 

 of the valves somewhat shifted ; this is so general that it would rather seem natural 

 than accidental. The convexity of both valves is perfectly the same. 



Locality, — In bluish and light brown sandstone near Parchairy, Serdamunga- 

 lum, &c. 



Formation, — Trichinopoly group. 



In Europe the species has been observed in the upper cretaceous strata of 

 the whole of Grermany, in Russia, &c. I am by no means certain whether 

 d'Orbigny's Fh. ( Cardium) Subdininense is really a different speciec. 



y 2. Pholadomya connectans, Forbes, PI. XVI, Eig. 29. 



1846. Ph. id., — Trans., Geol. Soc, London, vii, p. 140, pi. 17, fig. 5 — idem auctorum. 



Fh, testa ovato-elongata, incequilaterali, antice breviori et rotundata, postice 

 longiori ac sub-caudata, paululum angustiori, fere clausa ; tmibonibus prominulis, 

 antice versus incurvis, latis, approcuimatis ; superficie concentrlce striato-sulcata, ac 

 decern costulis radiantibus postice evanidis notata ; margine inferiori umbonibus 

 opposito sensim inflexo. 



Height of shell : its length ... ... ... ... 0"o2 



Thickness „ : „ ... ... ... ... 0-43 



This species differs from the next by a smaller number of radiating ribs, more 

 broadly rounded anterior end and the indentation of the margin opposite the beaks ; 

 to this indentation extends from the beaks a groove, which is broad, shallow, and 

 rather more conspicuous than other sulci separating the ribs. In front of the median 

 groove there are three and behind it seven radiating ribs, but on one of the two 

 valves there seems to be another small additional rib traceable on either side. 



Locality, — Pondicherry. I have seen but Eorbes' original specimen, of which 

 I give a figure ; the one supplied by Eorbes representing this shell is a little shorter 

 than it ought to be. 



Formation, — Valudayur group, 



sj 3. Pholadomya radiatula, Stoliczka, PI. Ill, Eig. 5. 



Fh, testa elongata, incequivalvi, antice ac postice rotundata ; margine superior I 

 et inferiori subparallelis, umbonibus mediocriter prominentibiis, incurvis, approxi- 

 mxUis ; supterficie striis incrementi, confertissimis ac costulis tenuibus radiantibus 

 numerosis in parte posteriori obsoletis ornata ; terminatione anteriori angustatim- 

 posteriori distincte, sed non precipue late, Mante, 



Height of shell : its length ... ... ... ... O'ol 



Thickness „ : „ ... ... ... ... 0'39 



In the large number of thin radiating ribs this species approaches the lower 

 cretaceous Fh, elongata, but is considerably higher in proportion to its length ; this 



