OF SOUTHERN INDIA. 113 



Again, as regards shells, the suggested distinction between the two divisions has 

 been strengthened by the general observation on recent oarinje, that their hinge 

 does not possess lateral teeth, wliile the tellinin^, as a rule, have them. But this 

 character loses its importance, inasmuch as there are many tellisinm which 

 have no lateral teeth, while, on the other hand, some of the species of Gari 

 have them distinctly indicated by a thickening of the margins in front and behind 

 the beaks. 



For these reasons I prefer to follow in my present arrangement the classifica- 

 tion suggested by Deshayes in 1830, separating, however, the Donacidje as a 

 distinct family according to Deshayes' more recent systematic changes. Merely in 

 order to facilitate the grouping of the various generic forms I shall accept two sub- 

 families, the G.iRiN,E f=JPsAMMOBiiD^j?J, and the tellininje. I look, however, upon 

 this separation more as a matter of some (not altogether) convenience, than as 

 being a strictly natural one ; however, a third division which I shall quote under 

 the name capsin^, including Macalia, Gastrana, Capsa, and Lucinopsis, appears 

 to me more desirable. The capsinji are distinguished by an elongated or rounded 

 shell ; they possess one or two cardinal teeth in each valve and no distinct 

 lateral teeth. 



I may add that the separation of the two former named sub-families is also 

 not distinctly indicated in geological history, except that some of the older secondary 

 species seem, as to form, to agree better with the first than with the second division. 

 Of the thu'd division there are more fossil species known, all of which agree in 

 general character with the recent ones. 



The species of Gari and Uiatula f^=SoletelUnaJ form connecting links between 

 the SoLENiD^ and the Tellinid^, and the capsin^ indicate a passage to the 

 Fetricolid^, belonging to the next order. 



a. Suh-family,— GARlNM. 



I shall take up this sub-family first, because the forms are more closely related 

 to those of former genera than are the true tellisinm. Deshayes in his new 

 edition of the Paris fossils refers to his family Psammobiidm only the genera 

 Psammobia, Sanguinolaria, and Capsa ; he altogether suppresses Soletellina as well 

 as his formerly proposed group Capsella. The genera which we refer here to the 

 sub-family answer more to those of H. and A. Adams', with a few alterations 

 which suggest themselves consequent on more recent researches. 



1. Gari, Schuhm., 1817, (Fsammohia, Lam., 1818). Shell rather thin, 

 elongated, nearly equilateral, posterior side somewhat less high, -nith one or more 

 ridges running from the beaks to the infero-posterior end ; sm"face regularly 

 concentrically striated ; hinge usually with two cardinal teeth in the right and 

 two in the left, the posterior of which often becomes obsolete; pallial sinus 

 large. The name G'ffj'i has been restricted for a large number of T(?^^i/ioif/ species, 

 the type of which may be considered Gari insigms. Other species have some 



2e 



