18 CHECK LIST OF THE 



narrow; a bony plate covering the cheek, similar to the plates on the top 

 of the head ; operculum with a broad dermal border ; branchiostegals ten 

 to twelve; no pseudobranchia; or opercular gill; no spiracle; gills four, a 

 slit behind the fourth ; gill membranes not connected, free from the isth- 

 mus ; two peculiar long lanceolate, olbiquely striate appendages on each 

 side of the isthmus, projecting backw^ard and covered by the branchio- 

 stegal rays, the anterior wholly adnate to the isthmus, the posterior free 

 behind; isthmus scaleless ; gill rakers stoutish, very short; scales of mod- 

 erate size, rather firm, cycloid, with a membranous border; lateral line 

 present; dorsal fin long and low, nearly uniform; the posterior rays not 

 much higher than the others ; tail somewhat heterocercal (more so in the 

 young), convex behind; no fulcrums ; anal fin short and low; pectoral and 

 ventral fins short and rounded, the ventrals nearer anal than pectorals; 

 vertebree amphicoelian or double concave, as usual among fishes, none of 

 them specially modified ; abdominal and caudal parts of the vertebral 

 column subequal ; air bladder cellular, bifid in front, lung-like, connected 

 by a glottis wath the pharynx, and capable of assisting in respiration , 

 stomach with a blind sac; no pyloric ca?ca ; no chased oviduct; intestine 

 with a rudimentary spiral valve. 



(7) Dogfish. Bowfin. Mudfish. 



(Amia cal\a.) 



Dark olive or blackish above, paler or sometimes bright green below , 

 sides with traces of dark greenish reticulations ; lower jaw and gular plate 

 often with round blackish spots; fins mostly dark, somewhat mottled. 

 Male with a round black spot at base of caudal lin above, this is sur- 

 rounded by an orange or yellow border; in the female this is very faint, 

 or more often wanting. 



Lateral line nearly median, directed slighth' upward at each end. 

 Scales on lateral line, about sixty-five. 



I)., 50; A., 10 to 12 ; v., 7. 



The female Dogfish is larger than the male, sometimes reaching a 

 length of twenty-four inches, while the male rarely exceeds eighteen. 



This fish is found generalK distributed in sluggish and weedy waters 

 from the upper St. Lawrence to the head of Lake Huron. I ha\e no 

 records for Lake Superior. It is one of the most voracious of our fishes, 

 feeding upon all forms of small fry and insects, and where abundant is 

 very destructive to the more Aaluable forms of fish lifi'. Its ilesh is said 

 to be soft, nauseous, and (juite uneatable. 



In May and June the Dogfish resort to weedy bays and marshes, 

 where they spawn, the parent fish remaining with the eggs until they are 

 hatched, and afterwards protecting the young for some time. 



