BIVALVIA. 13 
also resemble the impression of the adductor in some of the capuloid shells, more especially 
those of the Genus /tpponyz, in which the animal constructs a shelly base resembling a 
second valve, and the adductor in that Gasteropod has the twofold purpose of the Bivalve 
muscle, adhering to the shelly base as well as to the interior of the conical shell, forming 
and leaving a similar mark deeply impressed upon the inner surface of each piece, the muscle 
extending itself behind the foot, and this otherwise large “ belly-foot” of the Hipponyz is 
contracted to permit it to take hold of the shelly base. These impressions in Azomia 
indicate the presence of powerful muscles, although the animals possess little more than 
the rudiments of a foot. The genus is far removed from those animals which have only 
one piece of shell (the Univalve), but they are perhaps nearer than any other Bivalves, and 
they are, I think, appropriately placed here at the head of the list. 
In the recent state, this genus has an extensive geographical range, species belonging 
to it are found in America, India, Australia, the Mediterranean, and the North Seas. 
It is not numerous in species, either as recent or fossil. 
1. Anomia TENUISTRIATA, Deshayes. Tab. IX, fig. 1, a—e. 
ANOMIA STRIATA. J. Sow. (non striata, Broc., 1814). Min. Conch., t. 425, 1823. 
_— — Galeotti. Mém. Cour. par l’Acad. Brux., t. xii, p. 151, No. 89, 90. 
— epuHrpepium. Defrance. Dict. des Sc. Nat., t. 2, 1823. 
— eENutstrtaTa. Desh. Coq. Foss. des Eny. de Par., t. 1, p. 377, pl. 65, figs. 7—11. 
— — Sow. In Dixon Geol. of Sussex, p. 117, t. 4, fig. 8; and t. 14, 
fig. 17, 1850. 
— = ? Grateloup. Cat. des An. du Bas de la Gironde, p. 56, 1838. 
— uxvicata? WNyst. Coq. Foss. Belg., p. 311, pl. 26, figs. 4—6, 1843. 
— orpicunata? Id. - - - p.312, pl. 25, fig. 6, a, 0. 
— wineata. Jd. Sow. Min. Conch. Syst., index, 1835. 
—_ —_ Morris. Catal. Brit. Foss., p. 161, 1854. 
ANOMYA TENUISTRIATA. D’Orb. Prod. Paleont., p. 395, No. 1148, 1850. 
— sUBSTRIATA? Id. - - p- 396, No. 1150, 1850. 
— suBL&Zvieata? Id. - - p- 396, No. 1149, 1850. 
OstREA ANOMIALIS. Lam. Hist. des An. sans Vert., t. vi, p. 220, 1822. 
Spec. Char. A. testa tenui, suborbiculari, irregulari, valdé inequivalvt, valvd superiore 
convend, tenuissime striata, valvd inferiore plana foramine magno ; umbone submarginall. 
Shell thin, irregular, rounded, and finely striated externally ; upper valve much the 
larger and convex ; lower valve small, flat, and thin, with a very large opening for the plug ; 
umbo near the margin. 
Diameter, 2 inches. 
Locality. Alum Bay, Barton, Bramshaw, Brockenhurst, Brook, Bracklesham, Bognor, 
Clarendon, Stubbington, Whitecliffe Bay (Zdwards), Clewett’s Green, Newnham (Prestwich), 
Highgate (Wetherell). 
Belg., Env. de Bruxelles, Sables d’Uccle et de Foret (Nys?). 
France, Grignon, Montmirail, Senlis (Desh.), Blaye (Grateloup). 
