336 PALEONTOLOGY OF NEW YORK. 



Pal^oneilo tenuistriata. 



PLATE XLIX, FIGS. l-II, U ; AND PLATE XCIII, KIG. 13. 



Palaoneilo tenttMriata, Hall. Pi-clim. Notice Lamellibraiichiata, 2, p. 9. J 870. 



Pal. N. Y., vol. V, pt. 1. Plates and Explanations: PI. 49, figs. 1-12. 1883. 



Shell large, ovate-elliptical ; length more than one-third greater than the 

 height; basal margin regularly curving. Posterior end doubly truncate. 

 Cardinal line gently arcuate. Anterior end short, rounded. 



Valves convex, gibbous above the middle and in the umbonal region. 



Beaks at about the anterior third, moderately prominent, nearly straight, 

 little elevated above the hinge-line. The posterior end of the shell is 

 depressed-convex, with a more or less distinct depression extending to the 

 post-inferior extremity from just posterior to the beaks, giving a truncation 

 and slight constriction of the margin. 



Test thick, especially in the dorsal region. Surface marked by very fine 

 concentric striae, which are often crowded together on the basal and poste- 

 rior portions of the shell, forming irregular undulations of growth. In some 

 well-preserved specimens the concentric striae are elevated into sharp lamellae. 



Three specimens measure respectively 29, 33 and 37 mm. in length, and 

 18, 19 and 20 mm. in height. 



This species may be distinguished from P. fecunda by its finer and more 

 irregular surface striae and u.sually shorter form. 



Formation and localities. In the soft shales of the Hamilton group, on the 

 shores of Skaneateles, Cayuga and Seneca lakes ; at Pratt's falls and Delphi, 

 Onondaga county, and York and Moscow, Livingston county, N. Y. ; also from 

 Patterson's creek, Va. 



Palaoneilo fecunda. 



PLATE XLIX, FIGS. 13, 15-24. 



Pal(eoneilo fecunda. Hall. Prelim. Notice Lamellibranchiata, 2, p. 8. 1870. 



Pal. N. Y., voL V, pt. 1. Plates and Explanations : PI. 49, figs. 13-24. 188.3. 



Shell large, elongate-ovate; length nearly twice the height; basal margin 

 brosidly curving. Posterior end obtusely roiuided or doubly truncate. Car- 

 dinal line arcuate. Anterior end regularly rounded. 



