Calciferous of the Mohawk Valley 130 



slightly rounded. Pedicle valve convex, in some specimens some- 

 what carinate, beak projecting be3'ond the hinge line, brachial 

 valve much less convex and with a distinct mesial depression 

 along the middle of the valve. Surface marked by fine, radiating 

 striae of two kinds, the stronger alternating with from two to four 

 smaller ones, which increase by bifurcation and implantation. 



This species resembles O. macleodi Whitfield, but has not 

 the same arrangement of the striae. 



Locality. — Found near Ft. Hunter, N. Y., in No. IV 2. 



Dalmanella holiensis, n. s. PI. 17, fig. 9 



Shell sub-circular, hinge line less than the greatest width of 

 the shell. Cardinal angles rounded. Ventral valve convex, with 

 the greatest convexity near the beak. Beak extending somewhat 

 beyond the hinge. Surface marked by strong, radiating striae 

 which bifurcate from two to three times near the front of the 

 shell. Length and breadth 7 mm. This species differs from D. 

 ivcmplei in having coarser and fewer strice. 



Locality. — No. IV 2 of the Ft. Hunter section. 



SYNTROPHIA Hall and Clark 



Syntrophia palmata, n. s. PI. 17, figs. 14, 15, 16, 17 



Shell of medium size, moderately convex, length to width as 

 9 to II. Hinge straight, almost as long as the width of the .shell. 

 Ventral valve with a wide, poorly defined sinus which can not be 

 distinguished near the beak. 



Shell substance fibrous, which, in partially exfoliated speci- 

 mens gives a concentric appearance as .shown in fig. 14. 



In exfoliated specimens peculiar radiating lines are shown 

 which are probabW impressions of the vascular sinuses. This is 

 .shown in figs. 15 and 17. 



Size ri mm. in width, 9 mm. in length. 



This species bears a strong resemblance to Triplesia 

 {^Syntrophia') lateralis Whitfield. 



Locality. — In Nos. II 5 and IV i of the Ft. Hunter sedlion. 



