328 TESTACEOUS MOLLUSCA. 
* 
dorsal edge nearly straight; interior with two small central diverging 
branches which expand at their apices. 3. 8S. Africa. 
T. Pisum. Lam. 3.—Sow. Th. 1, p. 345, ¢. 69, f. 37, 8, 9— 
Kraussta P. Gray, Brach. p.110. Transversely suboyate, slightly 
reddish; valves nearly equal, with a few rather obsolete obtuse and 
rounded radiating ridges; margin slightly crenulated, not flexuous, 
deeply sinuated ventrally : mesial ridge and furrow broad and rounded. 
Upper valve slightly produced, very obtuse, with a large incomplete 
pertoration ; hinge-area small, linear ; deltidia small, nearly triangular. 
Dorsal edge of the lower valve rather broad, nearly straight : apophysis 
central, forked. -~,. Natal. 
T. Ateornsis. Sow. Th. 1, p. 362, t. 71, f. 91, 92.—Krauvssia A. 
Gray, Brach. p. 111. Suborbicular, slightly acuminated dorsally, 
rather lobed ventrally, radiatingly striated; mesial groove distinct, 
roundish ; perforation large, incomplete. Inner edge of the upper 
valve very minutely crenulated. ~,. Algoa Bay. Lower valve un- 
known. Not unlike the 'T. Natavensis of Krauss as delineated by 
Kuster (vii. 1, t. 2, b, f. 4 to 7). 
T. Lamarcnrana.—Kravussia L. Davids. Z. P. 1852, ¢. 14, 
f. 22, 8.—Gray, Brach. p. 111, f. 20. Suborbicular, striated with 
fine bifurcated ridges, light yellow; hinge-area well defined, flat ; 
perforation large, incomplete; deltidia small ; lower valve with a 
mesial furrow; apophysis central, bifurcated; margins of the valves 
thickened and spinulose within. }. Australia; N. Zealand. 
T. DesHayesu.—T. Carrnsis. Adams (not Gm.), Samar. p. 71, 
t. 21, f.4.—Kravussia D. Davids. Z. P. 1852, t.14, f. 20, 1—Gray, 
Brach. p. 111. Rounded-subtrigonal, rather produced at the beak, 
reddish brown, with about six red rays, thickish, radiatingly costated ; 
perforation moderate, incomplete; deltidia separate; lower valve 
depressed in the middle; apophysis central, forked. 3. Cape G. 
Hope. 
T. Fuavescens. Lam—T. Dentrata, Lam. 7.—T. AuvsTRALis, 
Quoy, Ast. t. 85, f. 1 to 5.—Sow. Th. 1, p. 349, t. 69, f. 25 to 33.— 
Watpuemia F. Gray, Brach. p. 58.—W. A. Woodw. t. 15. f. 4. 
Nearly oval, slightly acuminated dorsally, generally gibbous, some- 
times slightly flattened, whifish, yellowish, or brownish; valves 
unequal, smooth, generally more or less (sometimes very obsoletely) 
radiatingly grooved; margin scarcely flexuous laterally, more or less 
sinuated ventrally : mesial ridge and furrow broad, indistinct. Upper 
valve obtuse, reflected; perforation moderate, entire, round; hinge- 
area broad, rather indistinct, with rounded edges; deltidia large, 
united in the middle. Lower valve nearly circular, gibbous ; internal 
appendage as in Dorsata, the upper loop being very large. Margin 
generally toothed, teeth more or less numerous, large or small, 
