SALMONOID FISHES OF THE GREAT LAKES. 
23 
Description of type: Head 4.4 in body to base of caudal fin; depth of body 4; length of caudal 
peduncle from last anal to first caudaf rays 2 in head, its depth 2.87; eye 4.6; snout 3.87 to 4; inter- 
orbital space 3.5; length of maxillary from tip of snout 2.87; dorsal 10 (developed rays); anal 12; 
scales 8-76-7; branchiostegals 9; gillrakers 15 + 29, length .66 eye diameter. 
Body somewhat elongate, moderately deep, and compressed, very much resembling L. artedi; 
arched between snout and insertion of dorsal more than from insertion of dorsal to caudal, slightly 
more convex ventrally; caudal peduncle long, not deep as in L. artedi (some specimens of which it 
approaches, however), and compressed; head smaller than in L. prognathus, not full at nape; snout 
pointed, compressed, its outline continued by premaxillaries, lower jaw slightly projecting; maxillaries 
short in proportion to snout, reaching to anterior edge of pupil; distance from snout to occiput slightly 
less than half distance from occiput to dorsal insertion. 
Lateral line straight, scales moderate, thin. 
Dorsal fin inserted midway between snout and base of caudal, low, more so than in L. artedi, its 
longest ray a trifle less than .66 head, its base .66 of ray length; adipose fin rather small, as long as 
snout, measuring from insertion to free end; caudal widely forked; anal rather low, its longest ray 2.3 
in head, its base equal to ray length, its margin nearly truncate; pectorals and ventrals rather shorter 
than in L. artedi, being slightly longer than longest dorsal ray, the former not reaching more than half 
way to ventrals. 
Color in spirits silvery, slightly darker above, especially on removal of scales; cheeks silvery; 
dorsal fin dark on distal half, caudal broadly edged with black, other fins colorless save for very slight 
stipple on pectoral. 
As already indicated, this species, although a deep-water form, is very close to L. harengus, of 
which it is probably a deep-water variant. It is perhaps through L. supernas that the other deep-water 
forms are derived. Compared with L. harengus, L. supernas has a slightly deeper tail and the body is 
less slender. Two specimens of cisco, from off Knife River, near Duluth, differ from the others in the 
number of gillrakers, the number being about n + 21. Such variations were also noted by Evermann 
& Smith. These specimens are a little more robust than the others, with the adipose fin perhaps a 
trifle larger. For the present we can only record them as a variant of L. supernas. They differ from 
L. johannce in the slightly shorter snout, broader interorbital space, deeper body, and firmer scales. 
A copepod, apparently the same, is parasitic on both L. supernas and L. harengus. 
Leucichthys prognathus (H. M. Smith). Cisco of Lake Ontario; Ontario Longjaw; Bloater; “Chub. ” 
Coregonus prognathus Smith, Bull. TJ. S. Fish Comm., vol. xiv, 1894, p. 4, pi. 1, fig. 3, Lake Ontario at Wilson, 
New York ; type no. 45568, U. S. National Museum; coll., John S. Wilson. 
Argyrosomus prognathus, Evermann & Smith, Rept. U. S. Fish Comm. 1894, p. 314, 1896, pi. 26, Lake Ontario; 
Jordan & Evermann, Fishes North and Mid. Amer., pt. 1, p. 471, 1898 (after Smith). 
Habitat: Deep waters of Lake Ontario, in depths of 60 fathoms and more. 
This species is abundant in the western part of Lake Ontario in deep water. Whether any fishes 
from Lake Huron or Lake Michigan (here recorded as L. johannce) should be referred to this species is 
uncertain. It is distinguished by its projecting lower jaw and by the thick body. When taken from 
deep water the viscera become inflated under reduced pressure, hence the name “bloater” given to 
this and to the related species in the upper lakes. Our specimens of this species were taken by 
Dr. Seth E. Meek in Lake Ontario off Toronto. 
The following description is from a ripe female, 8+( inches long, from off Toronto, no. 4922 in 
the table on page 26. 
Head 4 in length to base of caudal; depth 3.5 (greater on account of ripe condition); length of 
caudal peduncle from last anal to first caudal ray 2.5 in head, depth nearly 3.5; eye 4; snout 4; inter- 
orbital space 3.57; length of maxillary from tip of snout 2.6; dorsal 10 (developed rays); anal n; 
scales 8-71-7; branchiostegals 8; gillrakers 15 + 29. 
Body moderately elongate, more convex ventrally, appearing, despite ripe condition of specimen, 
deeper than specimens from Lake Huron; caudal peduncle slender, tapering much, especially on ventral 
outline from anus; head large, thick at opercle, nape full and humped or strongly curved from occiput 
