252 CRETACEOUS PELECYPODA 



h. Cyclas, Klein, 1753. Shell orbicular, moderately compressed, tliin, 

 liino-e-teetli generally complete, but very small, surface witb regular concentric 

 stria3.of growth, covered with a kind of polished coating, which is angularly and 

 divaricately striated; type, Luc. cUvarkata, Linn. Species of this type already 

 occur in cretaceous deposits. 



List of cretaceous species. 

 a. CORBIN.E, vide genus Fimbria in Pictet and Campiche, Pal. Suisse, 4™« ser., 5™" liv., p. 283. 

 1. — F. corrugata, Sow., is the type of Sowerby's Sp/ucra and of Conrad's Palwocorbis 



(see p. 247). 



2-5. — F. gemmifera, P. and C, Michaillensis, P. and C, fibrosa, Forb., Ganllina, P. and R., 

 are not known by the hinge-teeth ; the forms agree with Corbis, excepting the first named species, 

 which may also be a Lucina (sub-genus CodakiaJ. 



6. — F. rotnndata, d'Orb., is the type of the genus Mntiella (see p. 247). 



7. — F. Verneuilli, Gueranger, {Corbis id., Album paleont. de la Sarthe, 1867, pi. xix, fig. 8), 

 is a small concentrically lamellated species of Mutiella. Gueranger also gives two figures on the 

 same plate of the last named species. 



8. — F. siriatocostafa, d'Orb., probably belongs to the same genus as the last, or to Splmriola. 



9. — F. Salignaci, Coq., not known from the hinge. 



10. — F. coardata, Zitt., is a Mutiella. 



11.12. — F. muUilamellosa and cublamellosa, d'Orb., uncertain. 



13. — F. Tevesthensis, Coq., from Algiers, appears to be a true Corbis. 



14,,— Corbis subleevis, Keys., (Petschora-reise, pi. 17, figs. 12-13,) is apparently a true Corbis, 

 and doubtfully referred by Eichwald to the Neocomien (Leth. ross., xi livr., 1867, p. 641). 



15-16. — Zuc. heteroclita, d'Orb., (Eichwald, ibid. p. 647,) is a Unicardiim, and the same may 

 be the case with Luc. rostrala, Eichw., (ibid. p. 649) ; both rather appear to resemble Jurassic mure 

 than cretaceous types. 



17. — Unicardium inornatum, d'Orb., {Card, idem. Pal. fran9. cret., pi. 256, figs. 3-6). 



18. — Fimbriella lavigata. Sow., sp., see p. 246. 



19.20. — Sjiharella concentrica, Con., Journ. Acad. N. Sc, Ph., ii, p. 280, is from the Alabama 

 cretaceous rocks ; and Sph. Oregon, Con., is quoted by Conrad from the lower eocene (? cretaceous) 

 of Oregon, (see Check-list eocene foss., Smith. Misc. Coll., No. 200, 1866, p. 6). 



In the South Indian cretaceous rocks the following three species occur : — 



21-23. — Mutiella exigua, Corbis ti/pica, and oblonga ; all are from the highest beds, the Arrialoor 



group. 



b. LVCININ/E, vide Lucina in Pict. and Camp., Pal. Suisse, 1. cit., p. 290. 



24-28. — L. Germani, vermicularis, Conmeliana, Bupiniana, and Roui/ana appear to be true Lucina. 



29. — L. Robinaldina is quite uncertain. 



30. L. globiformis, Leym., has more the form and structure of a Mysia (^= Diplodonfn) 



than of a Lucina. 



31. — L. Urgonensis, Lor., Rech. Geol. de la Savoie, &c.,par A. Favre, tom. i, 1867, p. 377, pi. c, 

 fi"-. 13 ; the posterior radiating striation of this species strongly recalls Linearia, (Tellinidje) . 



32. — L. ? solidula I woidd suspect to be a Mysia. 



33-34. — L. Faldensis and sculpta are apparently true Lucina. 



35. — L. Yibrayeana has the external form of the sub-genus Myrtea of Lucina. 



36-37. — L. Sancta-crucis and Arduennensis may rather belong to Mysia than to Lucina. 



38. — L. ? orbicularis, Sow. ; this looks more like a Limopsis than a Lucina. 



39. — L, pisum is a true Lucina, 



