SAL, MONOID FISHES OF THE GREAT LAKES. 
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coinciding when fin is supine, edge truncate, nearly perpendicular, base 2 in head; adipose moderate, 
equal in length, from insertion to tip, to interorbital space; caudal broad, widely forked, anal moderately 
high, its edge concave, first developed ray not reaching tip of last when supine; ventrals long, slightly 
more so than dorsal; pectoral still longer, 1.66 in distance from pectoral to ventrals. 
Color in spirits silvery, dark blue-black above, on tip of mandibles and snout, black on all fins, 
saving their bases, which are clear; ventrals, pectorals, and anal with less black than other fins; body 
colorless ventrally. 
Leucichthys cyanopterus Jordan & Evermann, new species. Bluefin. 
Type, no. 64672, U. S. National Museum, a specimen 16 inches long, from Lake Superior, off Marquette, Mich. ; 
coll., Mr. August J. Anderson. 
Habitat : Deep waters of Lake Superior. 
This species, closely allied to the blackfin, L. nigripinnis, is here described from the type and 9 
cotypes from off Marquette in Lake Superior. 
Head a trifle less than 4 in body length to base of caudal; depth of body 3.75; length of caudal 
peduncle from last anal ray to first of caudal 2.25 in head, its depth 2.8; eye 5; snout 3.5; interorbital 
space slightly more than snout; length of maxillary from tip of snout 2.8 in head; dorsal 10 or 11 
(developed rays); anal n or 12; scales 8-76 to 87-7, between occiput and dorsal about 33; branchi- 
ostegals 9; gillrakers 13 or 14 + 24 to 27. 
the type, a specimen 16 inches long, collected in Lake Superior off Marquette, Mich.) 
Body less elongate than usual, dorsally and ventrally equally curved; depth greater than usual 
not greatly compressed; width of body a trifle over twice in depth; caudal peduncle moderately long 
and deep, tapering from the proximal end to the caudal, and not more compressed than the body; 
head somewhat smaller than in related deep-water forms, but larger than in L. artedi; snout rounded, 
lower jaw usually the longer, but meeting the projecting premaxillaries; maxillaries extending nearly 
to a vertical from the front margin of pupil, and lying close to dentaries, so as to give them an oblique 
relation to the ventral body plane, distance from snout to occiput slightly more than half the distance 
from occiput to insertion of dorsal; opercular breadth about equal to snout or somewhat greater; eye 
rather large, less than interorbital space, the latter very slightly convex, straight in profile; snout 
slightly arched in profile. 
Lateral line straight, slightly nearer dorsal outline; scales moderate in size, equal, save on the 
caudal peduncle and on belly, showing blue-green luster when magnified. Dorsal fin inserted nearer 
snout than base of caudal, moderately high, its longest ray about 1.66 in head, its base somewhat 
over 2, its margin straight or slightly concave, first and last ray tips coinciding when supine; adipose 
rather large but variable, about 4.33 in head, and moderately high; caudal broad, widely forked, 
moderately deep; anal similar to dorsal in shape, but about 0.66 its height, its margin more concave, 
its base about equal to that of dorsal; ventrals long, reaching 0.75 distance to anal, and broad ; pectoral 
also long, reaching halfway or more to insertion of ventrals, and longer than the latter. 
Color in spirits silvery, darker above, with a bluish tint; dorsal fin dark on first ray and on distal 
half, but not dense black, as in L. nigripinnis ; caudal broadly margined with black in varying degrees; 
