FISH OF ONTARIO. 25 



barbel is slightly longer. The nasal barbel is one-half as long as the head. 

 Adipose fin low, beginning over the anal origin and is continuous with the 

 caudal. The ventral origin is under the end of the dorsal base, the fin does 

 not reach to anal origin. The caudal is rounded. 



Colour brownish without blotches. 



D. I., 6; A., 13 to 15; P .1., 8. 



This little Catfish rarely exceeds four or five inches in length. It 

 frequents slow streams and weedy ponds and has the habit of hiding 

 beneath stones and among water plants. As in Noturus, there is a poison 

 gland at the base of the pectoral spine. It is said to occur in the region 

 of the Lower Lakes, but as yet I have not found it. 



Order PLECTOSPONDYLI. (Carplike Fishes.) 



Soft-rayed or physostomous fishes, with the parietals broad, distinct ; 

 pterotic normal ; symplectic present ; opercular bones all present ; meso- 

 coracoid present ; no interclavicles ; the four anterior vertebrae much modi- 

 fied and joined together, provided with the Weberian apparatus or ossi- 

 cula auditus. Branchiostegals few, usually three or four ; shoulder girdle 

 attached to the skull. This group consists entirely of fresh water fishes, 

 and includes about eight families, to which belong the majority of all the 

 fresh water fishes of the world. The essential character of the order lies 

 in the modification of the anterior vertebrae, as in the Nematognathi, but 

 without the character of the rudimenary subopercle and maxillary and the 

 scaleless skin which distinguish the Catfishes. 



Suborder EVENTOGNATHI. (The Carps.) 



Plectospondylous fishes with the lower pharyngeals falciform, parallel 

 with the gill arches ; two upper pharyngeal bones ; brain case produced 

 between orbits ; jaws without teeth ; dorsal fin present ; no adipose fin ; 

 ventrals abdominal. Gill openings restricted, the gill membranes attached 

 to the isthmus. Streams and lakes of northern regions. Species very 

 numerous. 



FAMILY CATOSTOMID/E. (THE SUCKERS.) 



Body oblong or elongate, usually more or less compressed. Head 

 more or less conical. Opercles normally developed. Nostrils double ; no 

 barbels; mouth large or small, usually protractile and with fleshy lips. 

 Margin of upper jaw formed in the middle by the small premaxillaries, 

 and on the side by the maxillaries ; jaws toothless. Lower pharyngeal 

 bones falciform, armed with a single row of numerous comb-like teeth. 

 Branchiostegals three ; gill membranes more or less united to the isthmus, 

 restricting the gill openings to the sides ; gills four, a slit behind the 



3 F. 



