GREAT LAKES COREGONIDS 



505 



and abundantly. Even under such conditions the herring have been much reduced 

 in numbers, and with the increased effort that is certain to accompany the ever- 

 increasing prices paid for these fish the species stands in danger of being decimated. 



Leucichthys artedi of Lake Nipigon 



The Lake Nipigon herring is similar to the Erie form, except that it is not known 

 to grow so large. The largest specimen seen by me measured only 253 millimeters, 

 while in Lake Erie individuals of more than 300 millimeters are common. The 

 principal characters of systematic value that can be expressed numerically are 

 compared below for the forms of the two lakes. On account of the small size of the 

 Nipigon specimens the group of less than 225 millimeters is compared with the simi- 

 lar group from Erie (all of them necessarily albus, as no small artedi were collected in 

 Lake Erie) in those characters that are expressed in proportional values. Figures are 

 given also for a similar group of artedi from Lake Michigan. 



H/S: 



Erie, (3.6) 3.7-4 (4.2). 



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



Nipigon, (3.6) 3.7-3.9 (4.2). 

 Pv/P: 



Erie, (1.6) 1.8-2 (2.2). 



Michigan, (1.6) 1.8-2.1 (2.5). 



Nipigon, (1.5) 1.6-1.8 (2). 

 Av/V: 



Erie, (1.3) 1.4-1.6 (1.8). 

 Michigan, (1.3) 1.5-1.7 (2). 

 Nipigon, (1.3) 1.5-1.6 (1.7). 

 L/D: 



Erie, (2.8) 3.6-4 (4.3). 

 Michigan, (4.1) 4.4-5 (5.8). 

 Nipigon, (3.8) 4.1-4.6 (5). 



Gill rakers on the first branchial arch: 

 Erie, (41) 44-48 (53) . 58 

 Michigan, (41) 46-50 (55) . 60 

 Nipigon, (41) 46-49 (53) . 60 

 Lateral-line scales: 



Erie, (64) 71-81 (89). 

 Michigan, (68) 77-87 (94). 69 

 Nipigon, (65) 71-76 (81). 60 

 L/H: 



Erie, (3.9) 4.2-4.4 (4.7). 

 Michigan, (4) 4.2-4.5 (4.6). 

 Nipigon, (3.9) 4.1-4.3 (4.6). 

 H/E: 



Erie, (3.7) 3.9-4.1 (4.4). 

 Michigan, (3.5) 3.7-4 (4.3). 

 Nipigon, (3.5) 3.7-4 (4.1). 

 H/M: 



Erie, (2.5) 2.6-2.8 (3.1). 

 Michigan, (2.4) 2.7-3 (3.1). 

 Nipigon, (2.6) 2.7-2.8 (3). 



The figures show that the Nipigon race has, on the average, fewer lateral-line 

 scales, less body depth, and longer pectoral fins than the albus form of Erie. The 

 other differences can not be called significant in view of the disparity in the size of the 

 specimens in the two groups. In respect to other characters given for the typical 

 form under the general description the Nipigon form agrees rather closely, except that 

 possibly the jaw tends to be a trifle longer and the fin rays tend to be slightly more 

 numerous. Compared with small specimens of the artedi type of Michigan, which are 

 probably very like those that might be found in Lake Erie, the Lake Nipigon race has 

 still fewer lateral-line scales and still longer pectoral fins and probably also longer 

 ventral fins than albus, but its body depth is greater on the average. 



«» The number of Erie fish examined to obtain the figures for gill rakers is 313, for lateral-line scales 750. The proportional figures 

 are given for 125 individuals between the length limits of 128 and 224 millimeters, most of them more than 190 millimeters. 



" Figures for Lake Michigan so marked are based on an examination of 391 specimens ranging in length from 127 to 367 milli- 

 meters. AJ1 figures for proportions are given for the specimens less than 225 millimeters in length, 150 in number. 



w Figures for Lake Nipigon so designated are based on an examination of 84 specimens ranging in size from 138 to 253 millimeters. 

 In other computations pertaining to Nipigon specimens 71 individuals ranging up to 225 millimeters are represented, most of them 

 less than 190 millimeters long. 



