190 TELLINA. 



POLYGONAL TELLEN. 



80. Tellina polygona. T. testa alba, transversim striata, orbiculari, an- 

 trorsum angulata ; cardinis dentibus lateralibus nullis, primario ex- 

 porrecto, duplicato, alterius duobus. Linn. Gmel. p. 3244. 



Shell white, transversely striated, orbicular, the fore part angular ; hinge 

 without lateral teeth ; primary tooth projecting and double ; in one 

 valve two teeth. 



Chem. Conch. 10. pi. 170. f. 1650— 1653. 



Mont. Test. Brit. Suppl. p. 27. pi. 28. f. 4. Penn. Brit. Zool. 1812. 4. 

 p. 185. 



This species, which is not only angular before, but 

 in the middle of the shell, is described by Chemnitz, 

 under the name of T. Guinaica. Mr. Montagu has 

 also referred a small, rare, British shell, taken off Cra- 

 mond Island, in the Frith of Forth, to the same species. 



Foreign specimens inhabit the Indian Ocean, and 

 are an inch and a half in breadth ; the British shell is 

 not more than a third the size. 



DECUSSATED TELLEN. 



PL 43./. 2, 3. Linnean Society's Cabinet. 



81. Tellina decussata. T. testa suborbiculata, delicatissime decussation 

 striata; intus alba, cum lituris brunneis, vel purpureis variegata. 



Shell suborbicular, with very delicate decussated striae ; within white, 

 variegated with brown, or purple streaks. 



This is a whitish shell, with a faint rosy tip ; it is 

 rounded at both ends, but the fore part is produced, 

 like the T. crassa; the surface is finely striated trans- 

 versely, and crossed by delicate longitudinal striae : 

 the inside is white, marked with zig-zag lines of a red 



