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BRACHIOPODA.—3 GeEnERa. 
Shell bivalve, adhering to marine bodies, either directly or by a tendinous cord. 
Orsicuta.—Shell suborbicular, inequivalve; without any apparent hinge: lower valve 
very thin, flat, adhering to marine substances; the upper valve subconical, the 
summit more or less elevated. 
[I have not been able to meet with any shell agreeing with the above description. | 
‘TeREBRATULA.—Shell inequivalve, regular, subtriangular, attached to marine bodies by 
a short tendinous pedicle; the beak of the larger valve produced, often curved, 
perforated at the summit by a round hole, or by a notch: hinge with two teeth; 
two nearly osseous, slender, elevated, forked, variously ramified branches rise 
from the disk of the small valve, and serve as a support to the animal. 
(1) Shell smooth, without longitudinal strie or furrows. 
Plate XIII. Fig. 5. T. vitrea. (Anomia vitrea.—Gmel ) 
(2) Shell striated longitudinally. 
Plate XIII. Fig. 4. T. psittacea. (Anomia psittacea—Gmel.) 
Lixeuta.—Shell subequivalve, flattened, ovate-oblong, truncated at the summit, rather 
pointed at the base, elevated on a fleshy tendinous pedicle, fixed to marine bodies: 
hinge without teeth. 
Plate XIJI. Fig. 6. L. anatina. (Patella unguis.—Linn.) 
(a) Inside of ditto. 
