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PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxsvf. 



of orbit; caudal deeply forked, the lobes equal; length of fin about 

 an eye's diameter less than length of head ; height of anal contained 

 2| times in length of head; ventrals inserted below middle of base 

 of dorsal; length If in head; pectorals unusually long, 1^ in head, 

 reaching considerably more than half way to anal. 



Color silvery; dusky above; dorsal, caudal, pectorals, and anal 

 more or less suffused with black toward the borders, the anal much 

 lighter than the others. Ventrals immaculate ; none of the fins wholly 

 black, as in Argyrosomus nigripinnis. Scales loose, falling readil3^ 



Type. — This description is taken from the type, Cat. No. 62577, 

 U.S.N.M., a specimen 330 mm. long. It was obtained in Duluth, 

 Minnesota, by Mr. John Coventry, of Booth and Company, in Sep- 

 tember, 1908, it having been taken in deep water off Isle Royale. A 

 cotype. No. 13084, Stanford University, of the same size, and taken 

 at the same time and place, is apparently like the type, in all essential 



Fig. 3. — Argyrosomus zenithicus. 



details. Hundreds of specimens of this species were seen in the cold- 

 storage plant of Booth and Company, at Duluth, " the Zenith City." 



Argyrosomus zenithicus lives in much deeper water than the 

 ordinary lake herring, and makes a part of the autumn catch in deep 

 water. A large part of this catch, however, is of another species, 

 apparently undescribed, called the Bluefin. The present species is 

 locally known as Longjaw, and is more or less confounded by the 

 fishermen with the true Bluefin, which seems to be an ally of Argy- 

 rosomus prognathus., and with the Mooneye Cisco, Chub, Longjaw, 

 or Kieye {Argyrosomus hoyi), which occurs in Lake Michigan and 

 Lake Huron, but which we did not see in Lake Superior. 



From the Mooneye Cisco, Argyrosomus hoyi., as seen in Lake Mich- 

 igan, the Lake Superior Longjaw differs in being less silvery in color, 

 with the scales thinner, looser, and more dotted with black; in having 

 a much longer pectoral, in the longer head, longer jaws, and larger 

 adipose fin. The Blackfin Cisco, of Lake Michigan, Argyrosomus 

 nigripinnis, has the fins all black, the head shorter, the jaws shorter, 

 and the snout shorter. The pectoral is long in both species. 



