1855.] 341 



belong to that genus which seems to exist first in the Upper Silurian, and to rise 

 to the superior portion of the Jurassic Formation. It also resembles the Microdcn 

 ballastriata, Con., (Hamilton Group,) described in the New York Reports, part 4, 

 page 196, Geology, by James Hall. 



As the exterior form only is visible, the diagnosis must necessarily be very 

 curt. It may be thus characterized until better specimens shall be obtained. I 

 name it after Dr. Leidy, who first discovered it. 



Cypricardia Leidyi. 

 (Plate IV. The lower figure is magnified ten diameters.) 



Shell oblong, round before and truncate behind, very inequilateral, striate; 

 dorsal and basal margin parallel ; umbonial slope sharply carinate ; anterior 

 slope with an elevated line from the beak to the basal margin ; striae about 

 twelve, very regular, and nearly equidistant. 



Length 2-20ths, breadth nearly 4-20ths of an inch. 



Observations. This species is remarkable for its outline and striae. The dorsal 

 and basal margins being parallel, and the posterior margin perpendicularly 

 truncate, the angk=90 D . The striae cover the whole surface of the exterior, and 

 are bent at an angle of 90 at the umbonial slope. The shell is accompanied 

 on the specimen with some obscure impressed linear marks of a plant. 



The Report of the Corresponding Secretary for the last month was 

 read and adopted. 



Mr. Vaux, on behalf of the Publication Committee, presented the 

 Report for 1854, which was adopted. 



Dr. Rand offered the following resolution, which was unanimously 

 adopted : 



Resolved, That the privilege of admission to the Museum of the 

 Academy, and of endorsing tickets of admission to the same on public 

 days, be granted to Mrs, Margaret Harlan, widow of Dr. Richard Harlan, 

 late a member of the Academy. 



ELECTION, 



C, A, Santos, of Rio Janeiro ; C. Baptista d'Oleveira, Director of 

 the Botanical Garden of Rio Janeiro ; Jose Antonio G. y Garcia, of 

 Lima, Peru; and R. Ogden Doremus, M,D., of New York, were elected 

 (Jorresnonden ts. 



June 5M, 



Vice President Bridges in the Chair* 



Letters were read 



From the Society of Arts and Sciences of Batavia, dated June, 1854, 

 transmitting the volumes of its publications announced this evening. 



From the Royal Library of the University of Gottingen, dated Dec. 

 1, 185 1, acknowledging the receipt of the Proceedings, Vol, 6, Nos. 

 812, and Vol. 7, No. 1. 



From the Boston Society of Natural History, dated 22d May, 1855, 

 acknowledging the receipt of the Proceedings, Vol. 7, No. 7, and of the 

 Journal, new series, Vol. 3, No. 1, 



