OF SOUTHERN INDIA. 341 



Species of Barhatia are very numerous through all the sedimentary forma- 

 tions ; their number appears to increase gradually up to the present time. 



18. Area, Linn., 1799, fNavicula, Cihota, and Bijssoarca, auctorum). Shell 

 elongatcly sub-quadrangular, tumid, inequilateral, the anterior portion bcino- shorter 

 and ventrally more or less distinctly gaping; beaks distant, the ligamental hini-e 

 area being large and angularly striated; hinge line perfectly straight, with numer- 

 ous sub-equal transverse teeth estending over the entire length; type, ^. No<2, 

 Linn. 



Species of Area, as restricted, occur from the silurian through all the successive 

 formations up to the present time. The palaeozoic species have often been descri])ed 

 under Swainson's name Byssoarca, being a synonym of Browne's Cihota, under 

 which latter some Jurassic and cretaceous species have also been described. The 

 tertiaiy species of Avca appear to be more numerous than the recent ones. 



List of cretaceous species. 



a. AXIN^IX^E. 



The cretaceous species of this sub-family belong to the genera Tngonocmlia, Limopsis, Nucinella 

 and A.rhuea. 



1. — Tngonocmlia galeata, Miill., sp., (Cardhim Qaleatuin,^l\A\Q's:, Ojns galeafa, d'Orbigny, 

 et auctorum), is from the Seuouieu beds at Aachen, (ciJe Bosquet iu Starings Bodem v. Nederl. 

 ii. deel, No. 40S). 



Limopsis, (vide Pictet and Camp, in Pal. Suisse, IV«"= ser., 3™" part., p. 424). 



2-6. — L. Guerangeri and comjdanata of d'Orb., texlurata. Salt., calva, Sow., Emninghausi, 

 Miill. The two first are from France, the third from the Upper Greensand of Aberdeenshire, the 

 fourth from the Alpine Gosau, and the fifth from the Aachen deposits. 



7-9. — L. rhomboidalis, radiata, and Saclieri were described by Alth from the upper cretaceous 

 beds of Galicia, (vide Favre, Moll, foss, de Leniberg., 1809, pp. 121-123). 



\^-\\.—L. panmla, Meek and Hayd., and «;'/v«;'o-;;?(«e/«A<, Ev. and Shum., are fron> North 

 America (see Meek, in Smith. Misc. Coll., No. 177, 1864, p. 8). 



12-13. — L. iiUens and Oregoueiisis are quoted by Conrad from his lower eocene beds (Smith. 

 Misc. Coll., No. 200, 1806, p. 4). 



14. — L. transversa, Gabb, Pal. Calif., i, p. 200, is from the Chico group of California. 



Axinaa (vide 'Cat. de Pectunculus cretaces connus' by Pictet and Campiche in Pal. Suisse 

 !¥■"« ser., 3°"= part., p. 426). 



15-16. — Ax. 3Iarullensis, Leym., and alternata, d'Orb. 



Yi .—Pectunculus coneetdricus, Buvignier. The hinge of this species should be examined ; the 

 outline view given by Buvignier does not clearly indicate an AjcIum, and the form and ornamentation 

 of the shell remind us rather of a Uiucardium or Sphceriola (Lucixw.e), than of a species of A.cinaa. 



18-37.— ^J.-. sublavis, Sow., umlonata, Sow., subcoucentrica, d'Orb., subpulvinuta , d'Arch., 

 Eequieniana, d'Orb., lieuauxiana, d'Orb., Bourgeoisiana, d'Orb., Marrotiana, d'Orb., Norica, 

 T,\\.\,.,ohsoteta,G,(AiS.i.,ventruosa,G&\xi.,spinescens,^&\x^9., annulata, Rss., Reussi, d'Orb., lens, 

 Nilss., reticulata and insculpta, Rss., plana, Rom., snbdecussafa, d'Orb 



38.— ^r. obliqua is described by Schafhseutl in Siid-Bayern's Leth. geog., (1863, p. 158), 

 apparently from cretaceous beds of Southern Bavaria. 



