or SOUTHEEN INDIA. 477 



7. Lbnanoniia, Bouchard, 1850, teste Gray, (Cat. Flacent. and Anomiadce, 

 Brit. Mvis., 1850, p. 21). " Shell adherent, longitudinal, sub-equivalve, inequi- 

 lateral ; umbo curved to the right (regularly curved on each side) ; cardinal edge 

 transverse, oblique, inclined to the right ; valves thin near umbo, slightly radiately 

 ribbed ; lower valve with a sub-triangular notch near the umbo, lender the ear ; 

 cartilage ? muscular scar ? plug triangular, calcareous, with a narrow, scalariform 

 impression." Type, L. Gratjana, Bouch., from Devonian limestone near Bou- 

 longere. Three other species are indicated by Gray from the same beds. 



In external shape this genus is stated to resemble a Maclula f= LimaJ, but the 

 lower valve is adherent and provided with a perforation, as in Aiiomia. 



8. Anomianella proteus is figured by Bychholt from the carboniferous beds 

 of Belgium ; it is an ovate, thin shell, found attached to other shells ; there appears 

 to be no perforation in the lower valve, fvkle Mem. cour., Acad. Belgique, xxiv, 

 1852, Rychholt Mel. Paleont., pi. x, figs. 21 — 23). I have not met with any 

 detailed notice of the characters of this shell. 



9. Anomia, Linne, 1757. Somewhat irregularly sub-orbicular ; lower valve 

 attached, flattened or concave, perforated and notched near the minute beak ; 

 upper anterior or posterior part of the valve separate from, and often partially 

 overlapping, the thickened cardinal edge to which the ligament is internally 

 attached ; plug thick, entirely shelly, and free from the notch of the foramen ; 

 upper valve more or less convex, internally with three sub-central muscular 

 scars, Type, A. Ephqipium, Linn6. There are about 35 recent species known of 

 general distribution. 



For A. Bhjros (Proc. Zool. Soc., 1819, p. 118), which has the thickened 

 ligamental edge rather produced, the two lower scars of the larger valve small, 

 the upper one large, and is of a roundly sub-quadi-angular shape. Gray proposed the 

 sub-generic name Patro. The distinction from typical Anomice seems insignificant. 



10. JEnigma, Koch, 1845. Shell irregularly oblong or rounded, very thin, 

 inequivalve ; lower valve flat, with an excentric foramen, covered by a very thin 

 shelly lamina of the plug ; the lobes of the foramen partially overlapping each 

 other, but not closed ; their hind edge for the ligamental attachment barely 

 thickened; a partially open groove also runs from the beak of the upper, more 

 convex, valve to the edge ; uj)per scar large ; two lower smaller and distinctly 

 separate. Type, ^. cenigmatica, Chem. 



This form appears to deserve a generic distinction from Anomia ; it inhabits 

 brackish waters or estuaries. Heeve acknowledges only one species which lives 

 on foliage and on trees in the Mangrove swamps. A similar, and probably 

 distinct species occurs on the coast of the Bay of Bengal ; it was first met with 

 by Dr. J. B. Baxter at the Mutlah Biver (Port Canning, south-east of Calcutta). 

 I have also foimd it alive in the same locality, flatly attached with the entire 

 lower valve to old bricks, &c., which are only submerged during high water. 

 The animal slightly differs from that of Anomia. The same species also occm's 

 on the Burma coast and at Penang. 



6 a 



