362 PROCEEDINGS OF THE ACADEMY OP 



it and the Jamaica form, and through that with the Dominican, 

 is equally perfect. In short, the shells from Costa Rica and 

 Jamaica are the " missing links" between two well-marked and 

 distinct species. 



Galeodea lintea, Conrad (Proc. Phila. Acad. 1852, p. 199), from 

 the Vicksburg Eocene, is a shell of an entirely different type, and, 

 despite the opinion of that author, has no bearing on the present 

 question. It is a true Gassidaria, with imperfect varices, and is 

 tuberculated. 



EXPLANATION OF THE PLATE. 



Fig. 1, la, 16. G. laevigata. Adult. 

 Fig. 2. Gassidaria from Costa Rica. 



Fig. 3. C. laevigata, young, from Santo Domingo. Type of C. 

 subleevigata, Guppy. 



Fig. 4. G. striata, Lamarck. 



The following papers were ordered to be published in the Jour- 

 nal: "On the Batrachia and Reptilia of Costa Rica." By E. D. 

 Cope. 



"On the Reptilia obtained by Dr. John N. Bransford, U.S. N., 

 during the survey of Nicaragua of 1874." By E. D. Cope. 



The committee to which they had been referred recommended the 

 following papers to be published : 



