of Emmons, in Washington County, N. Y. 189 



surface depressed convex. Surface marked by fine concentric 

 lines and more rarely, fine radiating lines. 



The cast of the interior of the ventral valve shows four nar- 

 row elongate scars, radiating from the beak toward the front 

 margin. 



A cast of the interior of a dorsal valve shows fine vascular 

 markings and a well-marked median groove, also faint impres- 

 sions of the anterior adductor muscular scars and, also, what 

 may have been the adjustor muscular scars. 



This species is the representative, in the Middle Cambrian of 

 Lingulella Daiosoni (Bull. 10, U. S. Greol. Survey, p. 15, 1884), 

 of the St. John formation of the Lower Cambrian. It may also 

 be compared with Lingulella ferruginea, which ranges from the 

 Harlech beds through the Menevian and probably into the 

 period of the Lingula flags (Brit. Foss. Brach., vol. iii, p. 337). 

 Dr. Gr. Linnarsson figures a closely related species from the 

 Paracloxides beds of Sweden (Brach. Par. Beds of Sweden, pi. 

 Ill, figs. 24-28). 



Formation and Localities. — Cambrian. Limestones interbedded 

 in the Taconio shaly slates ; two miles south of North Granville ; 

 by the roadside a little west of the bridge crossing the Poultne}'- 

 Eiver at Low Hampton ; and on the roadside north of school 

 house No. 4, in the northeast part of Whitehall, Washington 

 County, N. T. 



LlNNARSSONIA TaCONICA., n. Sp. 

 Plate I, figs. 18-1 8d. 



Shell small, rarely exceeding 3 mm in length or breadth, usu- 

 ally circular to transversely broad oval. Ventral valve mod- 

 erately convex ; apex excentric; dorsal valve depressed convex; 

 beak obtusely pointed, marginal; surface of the valves marked 

 by fine lines of growth. 



In the interior of the ventral valve, near the posterior mar- 

 gin, oblique scars occur, one on each side of the raised rim sur- 

 rounding the foraminal opening in allied species. .From a 

 point of the foraminal rim a narrow depression extends ob- 

 liquely outward and forward, on each side, so as to enclose a 

 ys shaped elevation, that is strongly marked in casts of the 

 interior of the valve. The interior of the dorsal valve shows 

 two large oval scars, near the posterior margin, separated by a 

 low ridge that extends over three-fourths of the distance to the 

 front margin. 



This species is related to both L. transversa and L. sagittalis* 

 It differs chiefly in the characters of the interior of the dorsal 

 valves. As yet none of the specimens have shown the ventral 



* This Journal, III, vol. iz, pp. 114-111. 



