532 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 127 
the middle; strongly convex in lateral profile with the maximum convexity at 
about the middle; anterior profile strongly and broadly convex; umbonal and 
median regions swollen; lateral slopes short and steep; fold short, narrowly 
rounded, originating about 3 mm. anterior to the beak; anterolateral extremities 
separated from anterior end of fold by oblique grooves, swollen and rounded. 
Measurements in mm.— 
Brachial Hinge 
Length length Width width Thickness 
Hypotype (Carnegie Mus. 5457)..... 6.3 5.5 5.3 2.3 73 | 
4g T2320 3A) bes aici sis Mets He sore, ae 4.7 4.0 4.0 1.4 2.2 
Types—Figured hypotype: Carnegie Mus. 5457; measured hypotype: 
1232938. 
Horizon and locality—Crown Point formation in New York: On Valcour 
Island; quarry 4 mile northeast of the Normal School, Plattsburg, Plattsburg 
(15’) Quadrangle. 
Same formation in Vermont: On Isle LaMotte, Rouses Point (15’) Quad- 
rangle. 
Discussion.—This species was assigned by Raymond in his 1911 revision of 
the Chazyan brachiopods to O. longirostris Billings. The two species, however, 
do not seem to be the same. The apical angle of O. gracilis indicates a species 
with more attenuate beak than that of Billings’ species. Billings’ figures, how- 
ever, indicate a specimen with exceedingly acuminate beak. Examination of the 
type specimen, however, did not confirm this view. The pedicle sulcus of 
O. gracilis is longer, narrower, and deeper than that of O. longirostris. Con- 
sequently, the folds of the two species are different; that of Raymond’s species 
is usually longer, narrower, and more prominent. 
The New York and Vermont species is unlike O. obesa because of its less 
convex brachial valve, wider and shallower sulcus, and the greater length and 
narrowness of the fold. Raymond’s species is abundant in places in the Crown 
Point formation of the Chazy group. 
ONYCHOPLECIA KINDLEI Cooper, new species 
Plate 100, B, figures 4-10 
Shell small for the genus, subtriangular in otitline; sides gently rounded; an- 
terolateral extremities narrowly rounded; anterior margin straight to medially 
indented; apical angle about 70°. Anterior commissure narrowly uniplicate. 
Surface smooth, but exfoliated specimens are marked by fine, distant radial 
costellae. 
Pedicle valve subtriangular in outline, lateral profile gently to strongly convex 
with the maximum depth at about the middle; anterior profile moderately to 
strongly and broadly convex with a median depression formed by the sulcus. 
Umbo smooth and flat; sulcus originating on the umbo 4 to 1 mm. anterior to 
the beak, shallow and narrow at the posterior of the shell but deepening and 
widening anteriorly where it occupies about half the width; flanks bounding sul- 
