342 CRETACEOUS PELECYPODA 



39-43. — Ar. hamula, Mort., Siouxensis, Hall and M., iubventrieom, M. and Haj'd., rotundata, 

 Gabb, and subauatralis, d'Orb., are noted by Meek from North America in Smith. Misc. Coll., 

 No. 177, 1864, p. 8. 



44.4,6. — J_x. Veaichii, sagiUata, and cor are described by Gabb from California, (Pal. Calif, i, 

 1864, p. 197 et seq.). 



47. — Ax. Morloni, Conrad, from New Jersey, (Am. Journ. Conch., V, p. 44). 



Eichwald (Leth. ross., xmo Hvr., 1867, p. 576), suggests that Keyserling^s Fectuncului 

 Petschorce may be a Neocomien species of Axinaa. 



48-53. — Niicinella glahraia, Axinaa subplanata, levimla, altiuscula, subauriculata, and cardioides 

 represent this sub-family in the cretaceous deposits of Southern India. 



b. ARCIN^E. 



Pictet and Campiche note the species belonging to the present sub-family under the genera 

 Isoarca and Area (vide Pal. Suisse, IV™" ser., 3»« part., pp. 422 and 429 et seq.) ; I shall, therefore, 

 take the first genus and then the second, in which it will be necessary to point out the different 

 generic and sub-generic forms, as distinguished by later researches, and as far as admissible from 

 existing materials. 



54.58. — Isoarca alpina, globulosa, Agassizi, eostata, obesa* and supracretacea. 



59. — Isoarca gibba is the only species occurring in Southern India ; no species is known to re- 

 present the genus in America. 



Area and allied genera (see Pictet and Camp., 1. cit., p. 468). 



60. — Area marullensis, d'Orb., Baudouiana, Cott., ejjiscopalis, Cott., Aubersonensis, P. and C, 

 Dabiesiensis, P. and C, and Dupiniana, d'Orb., are Barbatia. 



61. — A. Jaecardi, P. and C, belongs to the sub-genus Acar. 



62-63. — A. Essertensis and llumbertina, Loriol, (Favre Res. geol. de la Savoie, &c., pi. C, 

 figs. 16 and 17,) belong either to Area, or perhaps rather to the sub-genus Calliarea. 



64-66. — A. sancta-crucis, P. and C, Carleroni, d'Orb., eomplanaia, P. and C, (non A. com- 

 planata, Chem., 1784, non Cueul. complanaia, Sow., 1840). 



67.—//. Eauliiii. Leymerie's original figure would indicate a Barbatia, -with. Hue r2iA\sii\ng 

 striiB and broadly incurved, somewhat flattened, beaks ; d'Orbigny's figure, supposed to be the 

 same species, would seem rather to represent a Cueulleea-\\ke shell, somewhat of the form of a 

 Trigonoarca or Nemodon. Either one or the other of these figures must surely be incorrect, or they 

 represent two distinct species. 



68. — A. Neocomiensis, d'Orb., may belong to the section called Nemodon by Conrad. 



69. A. secnris, Leym., is apparently one of the elongated forms of Scapharea, called by 



Conrad Nemoarca. 



70. — A. exseulpta, Koch, appears to be a Barbatia. 



71.75. A. Schusteri, Rom., Robinaldina, Cornueliana, and consobrina of d'Orbigny, and 



Villersensis, P. and C, are most probably Trigonoarca. 



76-83.— y4. Moreana, d'Orb., G'a6?7e/M, Leym., /?<?«»/3, Math. ( ?=Gahrielis, Leym.), cor and 

 ^^djem/^a of Matheron, Gresslyi axiik Salecensis, Loriol, Farusensis, d'Orb. The last is quite 

 insufficiently characterized; the two first ones are probably true Ciientlace, and the others Pictet and 

 Campiche suggest may all be varieties of A. Gahrielis ; the descriptions and figures published of them 

 are quite insufficient to enable an opinion to be formed as to the specific characters of these shells. 



84. A. ferrnginea, (non A.ferruginea, Reeve, which is an AmmalocardiaJ , is either a CucuUaa, 



or it belongs to the sub-genus Grammatodon. 



* = Isocardia Orhignyana. Leym. = Area isocardiiformis, Nyst. 



