324 TESTACEOUS MOLLUSCA. 



T. Cokeanica. Adains and Reeve, Samar. p. 71, t. 21, /. 3. — 

 Tekebratella C. Gray, Brack, p. 88. Subquadrangular. smooth, 

 pale brown, with crimson rays ; beak obtuse, with lateral ridges ; 

 upper valve convex, somewhat keeled in the middle ; lower valve the 

 more depressed, somewhat pinched near the sides ; hinge-area large ; 

 deltidia united ; perforation large, complete, angular at the sides ; 

 loop elongated, doubly attached. 1^. Corean Archipelago. 1 



T. Bouchardia. — Tekebratella B. Davids. Z. P. 1852, t. 14, 

 /. 4, 5, 6. — Gray, Brack, p. 88. Suborbicular, smooth, of a uniform 

 light yellow ; beak produced, recurved, furnished with lateral ridges, 

 and truncated by a large circular entire perforation ; deltidia united ; 

 hinge-area slightly concave ; lower valve depressed in the middle 

 ventrally ; loop elongated, doubly attached. 1-i-. 



T. Rubicunda. Don. Nat. Rep. t. 56,/. 2, 3, 4. — Sow. Th. I, p. 351, 

 t. 70,/. 45, 6, 7.— T. Inconspicua, Sow. Th. I, p. 359, 1. 11, f. 102, 3, 4. 

 — Terebratella R. Gray, Brack, p. 89. Nearly orbicular, rather 

 acuminated dorsally, red, gibbous, smooth; valves unequal, rather 

 irregular ; margin entire, slightly flexuous on the sides, its ventral 

 portion sinuated. Upper valve produced and truncated dorsally, its 

 perforation large, oblique and nearly entire ; cardinal area rounded ; 

 deltidia large, separate ; mesial ridge broad and prominent, angularly 

 rounded and obtuse on both sides. Lower valve somewhat pen- 

 tagonal, dorsally narrow, broad and somewhat angularly rounded in 

 the middle, slightly truncated ventrally; mesial groove broad and 

 distinct; loop elongated, doubly attached. 1. N. Zealand. 7 - 



T. Transversa. Sow. Th. 1, p. 361, t. 72, /. 114, 115.— Tere- 

 bratella T., Gray, Brack, p. 89. Transversely subovate, thin, pale 

 horn-coloured, smooth, merely wrinkled by the lines of growth. 

 Upper valve somewhat tetragonally ovate, very obtusely angular and 

 reflected dorsally ; perforation very large, incomplete ; hinge-area 

 large and flattened ; deltidia small and distant ; mesial ridge rounded 

 and indistinct. Lower valve transversely oblong, very obtusely 

 angulated dorsally ; mesial groove rounded, indistinct. Margin 

 entire, somewhat flexuous. l£...l T 5 T . 



1 This, the next thirteen species, and T. Evansii and Crenulata 

 (teste Davidson) belong to the subgenus Terebratella, which has 

 been thus defined : — " Loop elongated, reflected, doubly attached, to the 

 hinge-plate, and also to the longitudinal septum, by processes given 

 off at right angles from the crura near the centre of the valve." 



2 Woodward suggests that the Waltonia Valenciennei of David- 

 son may possibly prove the fry of this species with the reflected 

 portion of the loop wanting. 



