NO. 1596. DALMANELLAS OF THE CHEMUNG—WILLIAMS. ng 
Fig. 17 (Wv. 1A, 1h, No. 1), mold of interior of brachial valve. 
Fig. 8 (Wv. 1A, lvv, No. 5), mold of exterior brachial valve. 
Fig. 14 (Wv. 1A, Ivy, No. 1), mold of interior brachial valve. 
Fig. 6 (Wv. 1A, lvv, No. 2), mold of exterior of same specimen. 
The localities from which these types of the species come are: 
El. 6C.—Southeast corner of Catlin, Chemung County, 14 miles 
south of Pine Valley, on side hill above and west of the Northern 
Central Railroad tracks. 
Wy. 1A.—The ravine west of Spencer Lake, in northwest corner 
f town of Spencer, Tioga County, New York. 
The specimens come from the middle portion of the Cayuta mem- 
ber of the Chemung formation above the Dalmanella danbyi zone. 
DALMANELLA CARINATA Hall.¢ 
Plate IV, figs: 1,72; 4, and G. 
The distinctive specific characters of Dalmanella carinata are con- 
sidered to be its large size (25 to 85 mm. long and larger) ; its form, 
oval with the breadth greater than length, the greatest breadth above 
the middle line of growth; the brachial valve convex, the greatest 
convexity along the center from beak to front; the pedicle valve flat 
to coneave along the median line; in molds of the interior of the 
pedicle valve the muscular impression presents a flat to concave sur- 
face and elevated pointed beak, In extremely developed specimens 
the median carination in the pedicle valve is nearly obliterated by the 
broad inscoop of the surface. 
The cardinal process is wide and the trifid shtting of its end is con- 
spicuous; the crura are broadly divergent and strong. In molds of 
the interior of well-developed pedicle valves there is a narrow furrow 
running from the beak to the side of each muscular scar, representing 
(in- the original shell) an elevated linear ridge, about a millimeter 
distant from, and nearly parallel to, the inner face of the hinge teeth 
bounding the muscular scars. 
Specimens representing these characters from the U. S. Geological 
Survey collections are figured on Plate IV. | 
Wig. 4 (Wv. 1A, luuu, No. 1), mold of interior of brachial valve. 
Fig. 1 (Wy. 1A, lwww, No. 14), mold of interior of pedicle valve. 
Fig. 2 (Wv. 1A, lwww, No. 15), mold of interior of pedicle valve. 
The convexity of the brachial valve, the flat to concave form of 
the pedicle valve, and the elevation and flattening of beak of the 
pedicle valve produce a form similar to that of Orthothetes. 
TN. Y. Geol. Rept. 4th Dist., 1843,:p. 267; also Pal. N. Y., IV, 1867, p. 58, and. 
pl. vu, figs. 30, 31, and 32. The specimens selected from the Geological Survey 
collection as representing this species are Wy. 1A, luuu, Nos. 1 and 4, 15 and 14. 
