253 Systematic Paleoxtology — Middle Devonian 



surface is cancellated by concentric stria^ of equal strength, which are 

 rather widely spaced. In outline and general appearance this shell is 

 comparable with P. consimUis of the Chemung. The radii of P. con- 

 similis, however, are flattened and those of this species are rounded." 

 Kindle, 1912. 



Occurrence. — Eo]\ixey Foumatiox, Oxoxdaga Member. Xear Cum- 

 berland. 



Collection. — U. S. Xational Museum. 



[E. M. Kindle.] 



Genus LIOPTERIA Hall 

 LlOPTEEIA cf. COXRADI Hall 



Plate XXVIII. Fig. 13 



Leiopteria conradi Hall, 18S3, Pal. N. Y., vol. v, pt. i, plates and explanations, 



pi. XX, figs. 1, 2, 4. 

 Leiopteria conradi Hall, 1884, Pal. N. Y., vol. v, pt. i, Lamellibranchiata i, p. 



159, pi. XX, figs. 1, 2, 4; pi. Ixxxviil, figs. 1-4. 

 Liopteria conradi Clarke, 1903, N. Y. State Mus., Bull. 6.5, p. 426. 



Description. — Shell above the medium size, subrhomboidal ; length a 

 little greater than the height; anterior margin straight, nearly vertical; 

 basal and posterior margins regularly rounded. Valves subequally con- 

 vex; the left valve somewhat more convex than the right. Hinge-line 

 straight, longer than the length of the valve, greatly extended posteriorly. 

 Beaks acute, directed forward, prominent, situated near the anterior end 

 of the shell; iimbonal region gibbous. Ear short, separated from the 

 valve by a rounded depression or sulcus, extremity rounded; wing tri- 

 angular, much extended, margin concave, extremity acuminate. Test, 

 as indicated by casts or partially exfoliated specimens, marked by fine, 

 closely arranged, concentric lines of growth, which at irregular intervals 

 are crowded and raised into rounded or subangular fascicles, giving the 

 surface a decidedly undulated aspect; the striae become more crowded 

 upon the cardinal expansions, especially upon the ear. 



A partially exfoliated left valve in the Maryland Collection in outline 

 and markings resembles the above species to a considerable extent. The 



