OF SOUTHERN INDIA. 341 



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

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



18. Area, Linn., 1799, (Namcula, Cibota, and Byssoarca, auctorum). Shell 

 elongately sub-quadrangular, tumid, inequilateral, the anterior portion being shorter 

 and ventrally more or less distinctly gaping; beaks distant, the ligamental hinge 

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

 ous sub-equal transverse teeth extending over the entire length; type, ^. NocBy 

 Linn. 



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

 formations up to the present time. The palseozoic species have often been described 

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

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

 tertiary species of Area appear to be more numerous than the recent ones. 



List OF cretaceous species. 



a. AXINMIN^, 



The cretaceous species of this sub-family belong to the genera Tngonocoelia^ Limopsis, Nucinellaj 

 and Axinc&a, 



1. — Trigonoccelia galeata, MiilL, sp., (Cardmm galeatum,'Kvi\\QT, Opis galeata, d'Orbigny, 

 et auctorum), is from the Senonien beds at Aachen, (vide Bosquet in Starings Bodem v. Nederl. 

 ii. deel. No. 408). 



Limopsis, (vide Pictet and Camp, in Pal. Suisse^ ly^e ggj,^^ 3me part., p. 424). 



2-6. — L. Guerangeri and complanata of d'Orb., texturata, Salt., calva, Sow., Hoeninghaiisi, 

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

 fourth from the Alpine Grosauj and the fifth from the Aachen deposits. 



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

 beds of Galicia, (vide Favre, Moll. foss. de Lemberg",, 1869, pp. 121-123). 



10-11. — L. parvula, Meek and Hayd., and <s^^■^^^6'-J!?^^^^(?^f^^^^, E v. and Shu m., are from North 

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



12-13. — L, nitens and Oregonensis are quoted by Conrad from his lower eocene beds (Smith. 

 Misc. Coll., No. 200, 1866, p. 4). 



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



Axinaa (vide * Cat. de Pectunculus cretaces conniis^ by Pictet and Campiche in Pal. Suisse, 

 jyme ger., 3«^6 part., p. 426). 



15-16. — Ax. MaruUensiSj Leym., and alternata, d^Orb. 



17. — Pectunculus concentricus, Buvignier. The hinge of this species should be examined; the 

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

 of the shell remind us rather of a TJnicardkmi or 8plmriola (Lucinidj^), than of a species of AxincEa. 



18-37.-—^^. suhl(EVis, Sow., umlonata, Sow., sulconcentrica, ^'O^h., suJ)puhinata, ^' KY(i'\i,, 

 Bequienia7ia, d^Orb., Eemuxiana, d'Orb., Bourgeoisiana, d'Orb., MarroUana, d^Orb., Norica, 

 Z\it.,ohsoleta, (j(o\M. ,ventr2wsa, Ge'iJi., spi7iesce7iSjB.Q\x^Q, annulata, Rss., Beussi, d'Orb., lens, 

 Nilss., -reticulata and insculp)ta, ^^^., plana, Rom., suhdecussata, d''Orb 



38.— J^. (?5%^^ is described by Schafhseutl in Siid-B^yern's Leth. geog,, (1863, p. 158), 

 apparently from cretaceous beds of Southern Bavaria. 



v' 



