430 MITCHILL ON THE FISHES OF NEW-YORK. 



GASTEROSTEUS, STICKLEBACK. 



Generic character. 



Body somewhat lengthened. Dorsal spines distinct. Ventral fins 

 spiny. Abdomen carinated, or shielded on the sides, and bony beneath. 



1. Two-spined Stickleback. (Gasterosteus biaculeatus.) With two 

 spines in front of the dorsal fin. 



The smallest of our fishes, scarcely more than an inch in length ; and 

 known by the two thorny processes on the back, forward of the dorsal 

 fin. Seems to be the species described by Shaw ; and, what is remark- 

 able, the only one that I remember for which he has given credit to the 

 waters of New-York. Caught in the salt water among the killifishes. 



2. Four-spined Stickleback. {Gasterosteus quadracus.) With four 

 spines in front of the dorsal fin. 



In front of the dorsal fin four spinous processes irregularly situated. 

 Two similar spines in lieu of ventral fins. Connected with these on 

 each side a lateral spine reaching almost as far back as the vent. The 

 three foremost of the dorsal spines stiff; and the hinder one moveable. 

 Found, like the preceding, in the salt water among the killifishes. 



Rays, Br. 3. P. 13. D. 12. A. 11. C. 13. 



TBIGT.A. GURNARD. 



Generic character. 



Head large, mailed, and marked by rough lines. Gill-covers spiny. 

 Gill membrane seven rayed. Finger-shaped processes, in most species, 

 near the pectoral fins. 



1. Gurnard, or Sea Robin. (Trigla lineata.) With a line from 

 head to tail along and below the lateral line. 



