NOTES RELATIVE TO THE WHITE-FISH. 87 



the upper portion of the clavicle (Parker) narrows abruptly to a slender 

 blade. The premaxillaries, though higher, project forward, so as to ren- 

 der the snout more acute. The snout is shorter, as is also the maxillary. 

 The mucous tubes of the head are coarser and more prominent. 



From A. nigripmnis, described below, it differs in having a shorter 

 head, a more prolonged snout, slightly less length of maxillary and 

 mandible, as well as less width ot head and interorbital area. 



Body compressed ; deeper than in most of the species of the genus. 

 The height of the body is less than the length of the head. The dis- 

 tance from the snout to the nape is but little more than the length of the 

 mandible, (1.9 inches to 1.3 inches.) The width of the interorbital area 

 much less than length of snout. The length of the snout more than the 

 length of operculum. The length of the maxillary is more than the 

 greatest width of head. The muzzle is prolonged. The lower jaw ex 

 tends rather beyond the premaxillaries. The maxillary is long, reach- 

 ing beyond the center of the eye. The submaxilliary is long, and of mod- 

 erate width. The orbit is large. Minute teeth are present on the tongue. 

 The preopercular bone projects backward at the lower posterior angle. 



The height is .22^ of the length;* the length of the caudal peduucle,t 

 .IG ; the distance from the snout to the dorsal fin, .50 : the distance from 

 the snout to the anal fin, .71 ; the length of the head is .25|; the distance 

 from the snout to the nape is .19 ; the width of the head is .27f of length 

 of head; the width of the interorbital area is .20:^; the length of the 

 snout is .31 ; the length of the maxillary is .35; the length of the man- 

 dible is .51^; the diameter of the orbit is .24. 



Br., 9; D., 3-10; A., 2-10; C, 9-18-8; P., 15; V., 11; scales on lat- 

 eral line, 73; number of rows of scales above lateral line, S ; below lat- 

 eral line, 12. Length, 11.7 inches. 



National Museum, No. 1075G. Locality, Outer Island, Wisconsin, 

 Lake Superior. 



Argyrosomus nigripinnis Gill, (MSS.) 



Aryyrosomus n'ujripinnls (Gill, MSS.); Hoy, Trans. Wise. Acad. Sc, vol. 1, p. 100, 1372. 

 The black-fin % is not known from any locality thus fiir other than Lake 

 Michigan. It is found in the deepest portions of the lake, and is espec- 

 ially abundant in Grand Traverse Bay. Specimens were received at the 

 Smithsonian Institution from Dr. Hoy, in 1870. The only species closely 

 related to it is the one just described. From this it differs in the shorter 

 head, snout, maxillary, mandible, and the greater width of head and 

 interorbital region. There is a greater number of scales in the lateral 

 line ; the fins are more developed ; and the height of the fish is slightly 

 greater. It attains a much greater weight than A. Iloyi ; its average 



* Measured from premaxillaries along lateral line to end of scales. 

 t Measured from a point vertical to tlie last ray of the anal fin. 

 I For reference to habits, see page 35. 



