OE SOUTHERN INDIA. 



119 



the shells resemble externally Gastrana, but are much thinner. H. and A. Adams 

 apply, according to Morch, the name Homala, which is a corrected name of 

 Agassiz for Omala of Schuhmacher, for which the type T. planata of Linne 

 has been taken, and which is therefore identical with the next sub-genus. 



8m. Feroncea, Poli, 1791. Shell oblong, thin, anterior side short, posterior 

 elongated, sub-angular, with a slightly elevated marginal plicature ; ligament in a 

 long deep groove ; lateral teeth obsolete, cardinal elongated, but not very pro- 

 minent. Type T. planata^ Linn. 



8#. Metis, H. and A. Adams, 1858. Shell elongately oval, moderately in- 

 flated, anteriorly somewhat produced and rounded, posteriorly truncate, shortened, 

 and more or less plicated ; ligament large, in a deep groove, fulcra thickened inside ; 

 hinge in the right valve with two diverging teeth ; in the left the middle tooth 

 is distinct, but the anterior is represented only by a thickened margin; not a 

 trace of lateral teeth ; muscular impressions and pallial sinus large. This genus 

 is very characteristic and considerably different from other Tellince ; its type is 

 Tell. Meyeri, Phil., and such forms as T. lacunosa, Chem., Tell, spectabilis, and 

 many others of the same type, also appear to belong to it, but I have not seen 

 the last named shell. A species similar to spectahilis occurs fossil in the tertiary 

 deposits of Burma; it has the ligament marginal and almost covered by the 

 upper edge. Homes says (Possile Moll, des Wiener beckons, vol. ii, p. 92,) that 

 he satisfied himself of the identity of the miocene form with the recent one. 

 I have just now no materials for comparison, but as far as I can remember the 

 shell there are some not unimportant differences in the fossil form. In any case 

 the Vienna type is more equilateral than any recent specimen I have seen. 



H. and A. Adams refer to the sub- genus Metis merely the single species 

 Tell. Meyeri, Phil., and quote others like lacunosa, ephippium, &c., as a sub- 

 genus of Scrobicularia under the name Capsa, Bosc. I had no opportunity of ex- 

 amining all the species, but those which I have mentioned and a few others certainly 

 are more allied to the Tellinid^ than to Scrojbiculariid^ ; they have the ligament 

 soft or spongy, situated in a deep groove, sometimes merely covered by the free 

 sharp edges of the fulcra, but they have no cartilage proper, at least not separated 

 or lodged in a special cavity. The situation of the ligament is sub-internal, 

 perfectly similar to that of many Lucince. 



X'^si. Mactromya, Agassiz, 1842, (see Pict. Pal Suisse, 3«^^ ser., p. 154). Shell 

 elongated, equivalve, solid, sub -equilateral, posterior side somewhat longer, upper 

 margins sloping, almost straight, both ends rounded; hinge-teeth not known 

 (? ? wanting), an oblique internal rib in front of the beaks ; ligament strong, 

 external. Pictet and Campiche have again introduced Agassiz' genus for 

 the type species M. Couloni, and placed it in the Tellinid^. The authors have 

 examined specimens with the shell, which is very thick, only exhibiting stri^ of 

 growth ; they correctly conclude that the shell cannot belong to the Anatinibm, 

 which are all of a particularly thin structure. It is not easy to find anywhere 

 else a place for the genus except in the Tellinid^^ although no hinge-teeth have 



j/ 



