34 University of Michigan 



rather obsoletely hooked, several upper with sHght .grinding- 

 surfaces. Scales large, little smaller on median predorsal and 

 breast. L. 1. continuous, midway along side. Tubes simple, 

 extending well over scales about first half of exposed length. 

 Dorsal origin trifle nearer hind nostril than caudal base, fin 

 reaches half way to latter. Anal origin little behind dorsal 

 base, fin i 3/4 to caudal base. Caudal emarginate, lobes 

 pointed, similar. Pectoral 2/3 to ventral, latter inserted op- 

 posite dorsal origin, fin 4/5 to anal, not to vent which is close 

 before anal. 



Color in alcohol dull brownish, back a little darker than 

 lower surface. Fins dull brownish, all marked with slightly 

 darker shades of brownish on outer portions. Iris brassy. 



Length 165 mm. 



No. 2,113, A. N. S. P., cotype (type) of Ceratichthys cyc- 

 lotis Cope. "Michigan". E. D. Cope. Also Nos. 2,114 to 

 2,117, same data. 



Besides the above 13 examples from Belle Isle, Detroit, 

 from C. Rutter, and Grosse Isle from E. D. Cope. 



Couesius plumhcus (Agassiz) 



PLATE 9 



Ceratichthys prosthemius Cope, Trans. Amer. Philos. Soc. Phila., (2) 

 XIII, 1866, p. 365. Montreal River, Keeweenaw Point, Lake Superior. 



Head 4 1/4; depth 4 1/8; D. iii, 7, i; A. iii, 7, i; scales 57 

 in lateral line to caudal base and 3 more on latter; 11 scales 

 above 1. 1. and 8 below ; 33 predorsal scales ; head width i 3/4 

 its length; snout 3 1/6; eye 3 7/8; maxillary 3 1/3; inter- 

 orbital 3 ; least depth of caudal peduncle 2 3/5 ; pectoral i 1/5 ; 

 ventral I 1/2. 



Body elongate, compressed, deepest at dorsal origin, pro- 

 files alike, edges convexly rounded. Caudal peduncle com- 



