114 
PALEONTOLOGY OF NEW YORK. 
being lost. The teeth are supported by dental plates and between them lies a 
broad median ridge which narrows as it approaches the hinge. The brachial 
valve has a broad, full beak, which is closely incurved and concealed beneath 
the deltidium of the opposite valve. The cardinal process is large, erect and 
'slightly bilobed on its posterior margin ; it rests upon a short plate bearing two 
ridges which are continued into the bases of the crura. On either side of these 
ridges and just within the margins of the valve, is a strong, oval, concave, 
pouch-like plate. The crura are very long, passing into the primary lamellee 
without interruption. The spirals are relatively small, situated anteriorly, and 
consist of seven or eight volutions. These are connected by a simple erect loop, 
which is situated medially, and terminates at the junction of the lateral branches 
in a short, horizontal process. 
External surface of the valves covered with numerous radiating plications; 
occasionally smooth. Shell-substance fibrous, impunctate. 
Type, Terebratulites gryphus, Schlotheim. Stringocephalus limestone (Middle 
Devonian). 
Observations. Our knowledge of this old genus is still imperfect in many 
important respects, especially in regard to the 
muscular and other markings on the internal sur¬ 
faces of the shells. Mr. Davidson has elucidated 
the character of the spirals, loop, hinge-plate and 
cardinal process,* and his restoration of the 
brachial apparatus and its attachments is here in¬ 
troduced. 
Qdensted, in 1871, described! ^ shell from the 
Carboniferous limestone of Ratingen, as Uncites car- 
bonarius, a striated species, having the biconvex ex¬ 
terior of Uncites ; the form is, however, little known 
and its internal structure has not been demonstrated. 
Interior of brachial valve of Uncites gry- 
phus, Schlotheim ; showing cardinal 
process, marginal pouches, spiral and 
loop. (Davidson.) 
Geological Magazine, New Series, vol. viii, p. 145, 1881 ; and Devonian Brachiopotla, Suiipleinent, 
p. 30, pi. iii, figs. 5-10, 1882. 
t Op. cit., p. 520, pi. liv, figs. 47, 48. 
