26 
bulletin of the bureau of fisheries. 
Comparison oj Leucichthys prognathus and Leucichthys johannce. 
L. prog.na- 
ihus, 
Toronto. 
L. johannce, Cheboygan. 
Specimen no . . 
4922 
5280 
5281 
5279 
5277 
Length to base of caudal mm. . 
205 
210 
164 
160 
215 
Dorsal rays 
10 
10 
1 1 
9 
10 
Anal rays 
1 1 
1 2 
12 
1 1 
12 
Scales 
8-71-7 
8-78-7 
8-70-7 
8-73-7 
8-79-7 
Branchiostegals 
8 
9 
8 
8 
9 
Gillrakers 
15 + 29 
12+25 
13+26 
14 + 28 
14 + 26 
Sexual condition 
Ripe $ 
? 
? 
Ripe c? 
Unripe $ 
Comparative measurements:® 
Head. . . . 7 
O. 26 
O. 26 
O. 26 
O. 26 
O. 25 
Depth 
• 30 
• 27 
. 26 
• 25 
• 23 
Caudal peduncle — 
Length 
• 095 
• 105 
• 095 
. I I 
. I I 
Depth 
. 07 
. 08 
• 075 
• 075 
.08 
Eye 
. 065 
. 06 
■ 07 
. 072 
. 06 
Snout 
. 068 
. 07 
• 075 
• 07 
. 07 
Interorbital space 
. 07 
• 065 
• 065 
. 07 
■ 065 
Maxillary from tip of snout 
. 10 
. IO 
• 105 
• 105 
. II 
Opercular breadth 
• 07 
• 07 
• 075 
• 075 
• 07 
Subopercular breadth 
• 03 
. 02 
• 03 
• 03 
• 035 
Snout to occiput 
. 185 
• 185 
• 19 
• 19 
.185 
Ventrals to pectorals 
• 39 
• 36 
• 35 
• 35 
• 34 
Pectorals in pectoral-ventral distance 
2. 125 
2. 20 
2 . 00 
1 . 80 
2 . 00 
Pectoral length 
• 19 
• 17 
. 17 
• 19 
. 18 
Ventral length 
. 18 
• 17 
. 18 
. 19 
. 18 
Dorsal height 
. 165 
• 17 
■ 17 
• 19 
• 165 
Adipose length 
. 06 
. 07 
. 07 
. 08 
.08 
Anal height 
. 1 1 
. IO 
. 1 1 
. 1 1 
. 10 
a Measurements in hundredths of body lengths unless otherwise specified. 
Leucichthys nigripinnis (Gill). Blackpn of Lake Michigan. (PI. iv.) 
Argyrosomus nigripinnis Gill Ms., in Hoy, Trans. Wis. Ac. Sci., i, p. 100, 1872, Lake Michigan off Racine; name 
only. Hoy, Rept. U. S. Fish Comm, for 1872-73 (1874), p. 87, Lake Michigan off Grand Traverse. Jordan, 
Rept. Geol. Surv. Ind. 1875, p. 5, Lake Michigan. Jordan & Evermann, Fishes North and Mid. Amer., 
pt. 1, p. 472, 1898, Lake Michigan, Lake Mendota, and Lake Miltona, Wisconsin. Evermann & Smith, Rept. 
U. S. Fish Com. 1894, p. 317, pi. 27 (1896), Lake Michigan. 
Habitat: Deep waters of Lake Michigan and certain small lakes in Wisconsin. 
This is the largest of the deep-water ciscoes, and is a food fish of fine quality and of large commercial 
importance in Lake Michigan. It reaches a larger size than any of the other species of Leucichthys 
except eriensis, and is readily known by its black fins, in connection with its plump body and rather 
large eye and mouth. In Lake Michigan the fins are all chiefly black and the fish is called blackfin. 
In Lake Superior the species is replaced by the paler closely allied bluefin, Leucichthys cyanopterus. 
The following description is from our single specimen, 13 inches long, taken in Lake Michigan, 
off Kenosha: 
Head slightly less than 4 in body length to base of caudal; depth slightly more than 4; length of 
caudal peduncle from last rays of anal to first of caudal 3 in head, depth slightly greater; eye 4.66; 
snout 4; interorbital space 3.5; maxillary from tip of snout 0.5 longer than snout, 2.66 in head; dorsal 1 1 
(fully developed rays); anal 12; scales 8-75-8, between occiput and dorsal 34; branchiostegals 8; gill- 
rakers 18+33. 
Body moderately elongate, dorsal and ventral outlines symmetrical, not greatly compressed, its 
width 2.33 in greatest depth; caudal peduncle short and deeper than its length. Head moderate in 
length; snout not conical viewed from above, but rounded and broad; premaxillaries projecting very 
obliquely forward ; lower jaw longer, with slight symphyseal angle; maxillary not quite reaching anterior 
edge of pupil; distance from snout to occiput short, less than twice in distance from occiput to dorsal, 
and 2.5 times opercular breadth, which is slightly shorter than snout. Lateral line straight, nearer 
dorsal outline; scales moderate, of equal size anteriorly and posteriorly. 
Dorsal inserted slightly nearer head than base of caudal, relatively high, equal in length of first 
developed ray to the distance between the snout and occiput, a trifle more than 1.5 in head, all ray tips 
