GREAT LAKES COREGONIDS 



409 



other species of the lake in these lifts for a comparison with the depth relations of 

 these species as they are known in the Great Lakes. Zeniihicus comprised 13 and 43 

 per cent of the catches, respectively; nigripinnis 30 and 38 per cent (both in others of 

 the Great Lakes found in deeper waters); while the combined percentage of artedi, 

 nipigon, and clupeaformis (shallow-water forms) was 35 and 3 per cent. Thus, in 

 the set at 10 to 15 fathoms the deep-water zenithicus and nigripinnis had a combined 

 percentage of 43, and in the 30-fathom lift 81; while the rest, including reighardi, 

 which in other lakes show a preference for shallower water, had a combined percentage 

 of 55 and 17. A set made off Livingston Point on July 28, 1922, in 56 fathoms took no 

 reighardi. The specimens in the University of Toronto collection, so far as is known, 

 also were taken in shallow water, but it is not possible to state what proportion of the 

 catch they comprised. 



All the data thus indicate that reighardi occurs regularly on the shoals of the lake, 

 more abundantly in 10 to 15 fathoms than at 30, and is absent at 56 fathoms. These 

 conclusions that the species prefers the shallower waters are quite in accord with the 

 known habits of the species in the Great Lakes. 



BREEDING HABITS 



The specimens collected on October 26, 1922 (record 21), were not yet ripe but 

 were near maturity. It is likely, then, that the spawning time falls in November, 

 as in the case of the related form in Lake Superior. Nothing is known about the loca- 

 tion or the character of the grounds selected for spawning. 



Leucichthys reighardi dymondi (new subspecies) of Lake Superior 



The Superior form (fig. 18) is most like that of Lake Nipigon but in severa 

 particulars is rather intermediate between the Nipigon and Michigan forms. The 

 principal systematic characters of the three forms that can be expressed numerically 

 are compared below: 



Gill rakers on the first branchial arch: 

 Michigan, (31) 35-38 (43). 65 

 Nipigon, (32) 33-36 (38). 66 

 Superior, (32) 34-38 (42) .« 



Lateral-line scales: 



Michigan, (67) 72-81 (96) . 65 

 Nipigon, (64) 66-73 (77). 66 

 Superior, (65) 71-77 (83). 



L/H: 



Michigan, (4) 4.2-4.5 (4.8). 

 Nipigon, (3.5) 3.7-3.9 (4.1). 

 Superior, (3.7) 3.9-4.2 (4.4). 

 H/E: 



Michigan, (3.6) 3.9-4.2 (4.4). 

 Nipigon, (3.6) 4-4.4 (4.8). 

 Superior, (3.6) 3.9-4.2 (5). 



H/M: 



Michigan, (2.5) 2.6-2.8 (3). 

 Nipigon, (2.2) 2.3-2.5 (2.7). 

 Superior, (2.3) 2.4-2.6 (2.7). 



H/S: 



Michigan, (3.5) 3.7-4 (4.4). 

 Nipigon, (3.3) 3.5-3.6 (4). 

 Superior, (3.4) 3.6-3.9 (4.1). 

 Pv/P: 



Michigan, (1.8) 2.1-2.4 (2.8). 

 Nipigon, (1.4) 1.6-1.8 (2). 

 Superior, (1.5) 1.8-2 (2.4). 

 Av/V: 



Michigan, (1.2) 1.4-1.7 (1.8). 

 Nipigon, (1.1) 1.3-1.6 (1.7). 

 Superior, (1.2) 1.4-1.7 (1.9). 



88 These figures for Lake Michigan are given for 192 specimens of all sizes from the southern sector of the lake; most of them are 

 paratypes. Unmarked figures are given for 146 specimens ranging from 200 to 243 millimeters in length. 



88 These figures for Lake Nipigon are based on an examination of 98 individuals ranging in length between 145 and 304 millimeters. 

 Unmarked figures are given for 83 specimens 200 millimeters or more in length. 



87 These and unmarked figures for Lake Superior are based on an examination of 234 specimens ranging in length from 199 to 320 

 millimeters. 



