70 TESTACEOUS MOLLUSCA. 
mate smaller one in the other, no lateral teeth. 4. .3.—Hngland? 
— Guinea.—( Foreign specimens larger.) 
T. Capsorpes. Lam. 44. Broadly triangular, sub-equilateral, 
with transverse strize somewhat decussated by vertical ones, white: 
the angle of the anterior side with two grooves: no lateral teeth. 
1g.—Isle of St. Peter and St. Francis.—Not unlike Poly- 
gona. 
T. Decussata. Lam. 45. Rounded triangular, white with 
the beaks yellowish and nearly smooth, nearly equilateral, decus- 
sated by transverse stria and vertical grooves : hinge with lateral 
teeth.— New Holland. 
T. Brasrurana.* Lam. 46.--Lineata. Turt. Biv. p. 99. t. 
7. f.1. Triangularly oval, anteriorly angulated, thin, white usually 
tinged with rose-colour, nearly smooth, an oblique purplish rosy 
stripe (visible also in the interior) running from the beaks to the 
slightly longer posterior extremity: one valve with two cardinal and 
two lateral teeth, a single cleft cardinal tooth in the other. 2.. 2. 
—Rio Janeiro.— Approximating to Tenuis in shape. 
T. Ostiaua. Lam. 47.—An.T. Mapacascariensis. Gel. 
3237.?—D. p. 82.?—List. t. 386. f. 233.— Wood. G. C. t. 39. 
Sf. 3.1—W. t. 4. f. 46.2? Triangularly oval, the anterior side the 
longer and obliquely attenuated, posterior very short and rounded ; 
greyish, compressed and very finely striated transversely. 2.—/J/Zada- 
gascar.— Inflection of theanterior sideand margin scarcely apparent. 
T. Umponetia. Lam. 48. Small, subtriangular, convex, with 
the anterior side the shorter, and slightly angular, whitish with the 
the beaks hyaline, sub-antiquated, the transverse strie very fine. 
13.—New Holland. 
T. DetrorpaLis. Lam. 49.—Del. t. 6. f. 7. T. Uacrea. 
Ast. t. 81. f. 14,5, 6. Rounded, ovate, dirty white, compressed 
and transversely striated ; the anterior side obliquely attenuated and 
inflected ; one of the valves grooved ; hinge sub-central, with lateral 
teeth.— Variety. With the strize very elegant and the anterior side 
scarcely inflected. 12.—New Holland. 
T. Nympwauis. Lam. 50. Roundish-ovate, anterior side ob- 
liquely attenuated angulated and grooved, the posterior rounded and 
broad ; whitish with transverse strice towards the ventral margin, 
beaks smooth ; nymphee internal, dilated : hinge with very unequal 
cardinal teeth in one valve and a single one in the other, no lateral 
teeth. 13.— Guinea. 
T. Sotiputa.* Lam. 51.—W. t. 4. fi 84.—Wood. G. C. t. 
46. f. 2.—T. Zonata.— G'mel. 3238.—D. p. 100.— Lis. t. 405. f. 
250.—T. Ruspra. Da Costa. t.12. f. 4.—Psamnmosia 8. Turt. 
B.p. 95. t. 8. f. 2. Rounded triangular, thick, ventricose some- 
what angulated and compressed anteriorly, passing from white into 
yellow or pink with darker bands and obsolete ridges of growth : 
