Acad. Coll. signifies that specimens are in the Maryland 

 Academy of Sciences. 



S. I. Specimens are in the Smithsonian Institntion, at 

 Washington. 



Fins. — D. Dorsal, i. e., on the back; sometimes two in num- 

 ber. 



P. Pectoral ; attached behind the gill-covers. 



Y. Ventral ; attached to the lower side in front. 



A. Anal ; attached to the belly near the vent. 



C, Caudal ; the tail fin. 



