326 TE3TACEOU9 MOLLUSCA. 



Hexuou8, crenulated ; mesial groove and ridge broad, obtuse. Upper 

 valve acuminated dorsally, reflected, truncated ; perforation rather 

 large, incomplete; hinge-area large, broad, rather flattened, with 

 small triangular deltidia. Lower valve rather triangular, with a 

 rather acute apex, its dorsal edge sloping : internal appendage an 

 elongated reflected loop attached to a central septum. 1-|. Straits 

 of Magellan. 



T.Flexuosa. Ki?ig,Z.J.5,p.337.— Sow.Tk.l,p.Ml, £.69,/.23,4. 

 — Teeebeatella F. Gray, Brack, p. 87. Rouuded-subtetragonal, 

 rather gibbous, palish brown ; valves unequal, with radiating pro- 

 minent obtuse ridges ; margin crenulated, somewhat flexuous at the 

 sides, sinuated ventrally : mesial ridge and furrow broad, but rather 

 indistinct. Upper valve rather obtuse and reflected dorsally, its 

 sides bending inward ventrally ; perforation large, not complete ; 

 hinge-area large, broad and flattened ; deltidia small and triangular. 

 Lower valve broader than long, rather flattened ; internal appendage 

 as in the last species. 1 J. Straits of Magellan. 



T. Chilensis. Brod. Z. P. 1833 ; Z. T. 1, t. 22,/. 1.— Sow. Th. 1, 

 p. 347, t. 68, /. 18, 9. — Teeebeatella C. Gray, Brack, p. 88. 

 Somewhat transverse, suborbicular, slightly gibbous, pale ; valves 

 nearly equally convex, with numerous obtuse, scarcely prominent 

 ribs ; margin crenulated, nearly straight, sinuated ventrally. Upper 

 valve dorsally obtuse, with inclined sides, and a broad very obtuse 

 longitudinal central ridge; perforation large, nearly entire; hinge- 

 area large, broad and flattened ; deltidia triangular, moderate. Lower 

 valve transversely ovate, rather flattened, with a broad distinct central 

 groove ; apophysis three-fourths the length of the valve, forming 

 loops, as in T. Doesata. tV'-tV Chili. 



T. Soveebii. King, Z. J. 5, p. 338.— Sow. Tk. 1, p. 348, t. 68, 

 /. 20, 1, 2. — Teeebeatella S. Gray, Brack, p. 88. Rounded- 

 subtetragonal, rather flattish, of a somewhat rusty brownish ; valves 

 unequal, smooth, with very obsolete and inconspicuous radiating 

 ridges ; margin very slightly crenulated, somewhat flexuous, with a 

 rounded ventral sinuosity. Upper valve obtuse dorsally, slightly 

 reflected, with its sides inclined inward ; mesial ridge rather obsolete, 

 broad and rounded ; perforation large, incomplete ; hinge-area large 

 and flattened, deltidia small and triangular. Lower valve flattish, 

 somewhat triangular, rounded ; mesial groove broad, indistinct ; in- 

 ternal appendage as in Doesata. 1 t 5 t . Straits of Magellan. 



T. Ceuenta. — Anomia C. D. p. 295. — T. Sanguinea, Lam. — 

 T. Zelandica, Desk. Mag. Z. 1841, t. 42.— £W. Th. 1, t. l%f. Ill, 

 2, 3. — Teeebeatella C. Gray, Brack, p. 89. Subtransverse, sub- 

 orbicular, slightly acuminated, ventricose, rather thick, red ; valves 

 unequal, with crowded radiating dichotomous costella3 ; margin crenu- 



