24 
BULLETIN OF THE BUREAU OF FISHERIES. 
to insertion of dorsal; snout bluntly rounded, broad; lower jaw projecting markedly, a slight angle at 
symphysis of dentaries, giving jaw a slightly hooked appearance; premaxillaries not breaking contour 
of head noticeably; lateral projection of anterior ends of preorbitals and maxillaries greater than usual; 
maxillaries extending to below middle third of eye, their supplemental one-half their breadth and 
length; distance from snout to occiput long, half distance between dorsal and occiput; opercular breadth 
equal to snout. 
Lateral line rising slightly anteriorly, but nearly straight; scales moderate, slightly larger ante- 
riorly, easily detached. 
Dorsal fin inserted nearer base of caudal than snout, moderately high, its longest ray about 1.5 in 
head, its base 2.5, its margin truncate; adipose moderate (somewhat shrunken in preservation), slightly 
shorter from insertion to tip than snout; ventrals and pectorals a trifle, the latter noticeably, longer 
than dorsal, pectoral reaching half way to ventrals; anal slightly concave; adipose eyelids and pectoral 
fold not prominent; caudal forked widely but not deeply. 
Color in spirits, suffused with brownish, darker above than in Lake Huron specimens; lateral line 
marked with line of distinct black in specimen at hand; fins clear, dorsal and caudal dusky on distal 
halves; ventrals, anal, and pectorals with only slight traces of black stipples on first rays and margins. 
From the bloater of Lake Michigan, which we here call Leucichthys johannce, the Ontario fish differs 
in its darker coloration, the more projecting lower jaw, the slenderer caudal peduncle, the greater depth 
of the body, and the greater distance between the pectorals and ventrals. From typical examples of 
Leucichthys johannce, it also differs in the much larger number of gillrakers. But as stated later, part 
of our specimens from Lake Huron, referred to L. johannce, have the gillrakers much as in L. prognathus. 
What this difference means is a matter demanding further study. 
Leucichthys johannae (Wagner). Lake Michigan Cisco; Bloater oj Lake Michigan. (PI. in. ) 
Argyrosomus johannce Wagner, Science, n. s., vol. xxxi, no. 807, p. 957-958, June 17, 1910, Lake Michigan, in about 
25 fathoms, some 18 miles off Racine, Wis. Type no. 372c!, Wisconsin Geological and Natural History Survey. 
The bloater is very common in the northwestern part of Lake Huron in deep water, and also for 
the whole length of Lake Michigan. On these lakes it is not often taken to the markets, and is not 
highly valued as food. It is a great nuisance to the fishermen, large schools entering the nets and 
tangling them, although the mesh is large enough to allow escape. 
Whether the form in Lake Huron and Lake Michigan is really distinct from the prognathus of Lake 
Ontario is a matter we can not finally determine. Some examples of johannce may be known at once 
by the few gillrakers, but this character is lost in Lake Huron examples, which, for the present, we are 
forced to refer to the same species. 
The following is a description from four specimens, 7 to 10 inches in length, two from Lake Michigan 
near Chicago and two from Lake Huron off Cheboygan, Mich.: 
Head 4.2 in body length to base of caudal; depth of body equal to head; length of caudal peduncle 
from last anal to first caudal ray 2.4 in head, its depth 3.5; eye 4.4; snout 3.75 in head; interorbital 
space equal to snout; length of maxillary from tip of snout 2.66 in head; dorsal 11 (developed rays); 
anal 12; scales 8-76-8 (8-74 to 80-7 or 8), branchiostegals 9; gillrakers on first arch 11 + 23. 
Body moderately elongate, not greatly compressed nor deep, its depth 1.66 its width; more convex 
ventrally (possibly on account of being brought from a depth and blown out by reduced pressure) ; 
without nuchal hump; caudal peduncle long, not deep, somewhat compressed; head moderately long, 
somewhat less than the average of L. zenithicus; distance from snout to occiput moderately long, 
equal to half distance from occiput to insertion of dorsal; eye moderate; maxillary rather long, reaching 
to below anterior third of pupil, without decurving strongly on free edge from junction with premaxil- 
laries; premaxillaries continuing contour of head at but slight angle; snout rather long and rounded, 
lower jaw projecting beyond it somewhat with a small symphyseal angle; suborbitals narrow, pre- 
orbitals rather broad. Lateral line straight, scales moderate in size, thin and flexible. Dorsal fin 
inserted midway between snout and base of caudal, moderately high, border truncate, adipose moderate, 
from insertion to free end somewhat longer than snout; pectoral and ventral rather short, latter not 
