186 Storer^s Description of^ and Observations 07i, 



The ventral fins commence just back of the middle of the 

 Ijody — and are about two inches in length. 



The anal fin commences anterior to the second dorsal, 

 and is not continued as far back as the posterior extremity of 

 that fin. 



The length of the upper lobe of the caudal fin is equal, as 

 was observed by Valenciennes, to the width of the head. 

 The lower lobe is equal in length to one-third of the upper lobe. 



This description is necessarily imperfect, being drawn up 

 from a dead specimen ; but as I have never before seen 

 a specimen which had been taken in our waters, I was un- 

 willing to let it pass unnoticed. 



The confusion which existed in the genus Zygcena — the 

 mistakes which were constantly made by Ichthyologists when 

 speaking of the different species, led Valenciennes to prepare 

 a monograph of the genus, which was published, illustrated 

 with admirable plates, in the ninth volume of the '' Memoires 

 du Museum d'Histoire Naturelle." 



The plates of Shaw and Strack, and others who copied 

 from them, were calculated to mislead ; but the figures of 

 Valenciennes, accompanied with clear descriptions, settle the 

 species with precision. 



Dr. Yale informed me that a formidable species of Sting- 

 Ray was found at Holmes' Hole, which he had frequently 

 seen. As I had never had an opportunity of examining this 

 species, I was not ready to consider it the pastinaca, the com- 

 mon Sting-Ray, found on the shores of Great Britain, — and 

 made therefore a simple reference only, in my Report, to a 

 species of Trygon being found along our coast. In October 

 1840, Dr. Yale sent me the head and tail of a species " whose 

 whole length" he stated " including the tail, was ten and a 

 half feet : its breadth was four and a half feet at its widest 

 part." The jaws were furnished with numerous rows of 

 rhomboidal teeth. The tail was six feet and three inches 

 long ; more than four inches wide at its origin, and tapering to 

 a point at its extremity. A single row of spines was situated 

 at the commencement of the tail — and six or eight inches 



