78 HISTORY OF THE FISHES OF MASSACHUSETTS. 



The caudal is even at extremity. 



In some specimens the membrane connecting the rays of the second dorsal, anal, 

 and caudal fins extends to their extremities, causing the fins to appear even at their 

 edges ; while in others the extremities of the rays project like those of the pectorals 

 and ventrals. 



The fin rays are as follows : D. 9 - 16. P. 17. V. 3. A. 14. C. 12. Length 

 10 to 18 inches. 



Remarks. This is our most common species of Cottus. As the " Sculpin " or 

 " Toad-fish " it is well known, and is the pest of the numerous boys and idlers who 

 at certain seasons of the year are constantly fishing from the wharves and bridges for 

 more marketable species. 



Mitchill described this species in his "Fishes of New York," under the name of 

 octodecimspinosus ; but as it has the same number of spines as the Cottus scorpius, 

 its specific name alone cannot distinguish it ; and as it was previously called by Wil- 

 loughby Virginianus, from a specimen sent him by Lister from Virginia, I have no 

 hesitation in prefixing his specific name to my description. 



Newfoundland, RICHARDSON. Massachusetts, STORER. New York, MITCHILL, 

 DEKAY. Virginia, WILLOUGHBY. Labrador, H. R. STORER. New Brunswick and 

 Nova Scotia, PERLEY. 



The Acanthocottus teneus I now omit, thinking I have previously mistaken for it a 

 variety of A. variabilis of Girard. 



GENUS V. BOLEOSOMA, DEKAY. 



The form of the body is that of a dart ; the head is very short, rounded like an 

 arc of a circle, below which the mouth, generally small and slightly protractile, opens 

 horizontally ; the upper jaw sloping over the lower. The neck and the sides of the 

 skull compressed. The opercular apparatus and the cheeks covered with scales. 



BOLEOSOMA OLMSTEDI, Agassiz. 



The Tessellated Darter. 



(PLATE IV. FIG. 4.) 



Etheostoma Olmstedi, STOKER, Bost. Journ. Nat. Hist., IT. p. 61, pi. 5, fig. 2. 



" " A YKKS, Bost. Journ. Nat. Hist., IT. p. 257. 



Percina minima, HALD., Journ. Acad. Nat. Scien., Tin. p. 330. 

 Boleosoma tessellation, Tessellated Darter, DEKAY, N. Y. Report, p. 20, pi. 20, fig. 57. 

 Perca minima, DEKAT, N. Y. Report, p. 7. 



