28 



SCIENCE 



[N. S. Vol. XXXII. No. 809 



later down terracing, the Catskill encountered 

 a rock-ridge near its moutli and developed be- 

 hind it an interesting meander-curve at about 

 the hundred-foot contour in West Catskill, 

 left as an elevated oxbow. 



The entire problem deserves more extended 

 field work. George H. Chadwick 



Canton". N. Y., 

 .June 3, 1910 



J ON THE STICKLEBACK OP LAKE SUPERIOR 



In 1850 Louis Agassiz^ described a stickle- 

 back from Lake Superior which he called 

 Gasterosteus pygmwus. The species was 

 founded on three specimens, one less than 

 eleven sixteenths, the other two less than one 

 quarter of an inch long. The description 

 given of these covers somewhat over a page. 

 Most of it, however, would apply equally well 

 to any form of the genus Eucalia, and there 

 are only the following characters which seem 

 of value as a basis for differentiation : the 

 small size (Agassiz seems to have considered 

 his largest specimen as representing the ap- 

 proximate maximum for the species) ; the 

 relation of length to depth (eleven sixteenths 

 of an inch, or less, to one eighth or one seventh 

 of an inch) ; the dorsal fin formula (VI.-7 

 [?]); and the anal fin formula (L-6). The 

 supposed species is not discussed by Jordan 

 in the paper in which he first fully describes 

 the genus Eucalia, although the name is men- 

 tioned.^ Eigenmann, in his review of the 

 North American Gasterosteidse,^ includes it 

 as a variety of Eucalia inconsians; and in 

 this form it is taken over into Jordan and 

 Evermann's " Fishes of North and Middle 

 America."* This last work has taken over 

 bodily Eigenmann's notes on the form, which 

 notes are, however, inaccurate in ascribing to 

 pygmcea a deeper body than to inco7}stans. 

 I can discover no such character in Agassiz's 

 original description. Supposing his largest 

 specimen to have been only ten sixteenths of 

 an inch long, and its depth to have been one 



^" Lake Superior," p. 314; Plate IV., Fig. 1. 

 'Proc. Ac. Nat. Sci., Phila., 1877, p. 65. 

 'Proc. Ac. Nat. Sci., Phila., 1886, p. 233. 

 ' Bulletin 47, U. S. Nat. Museum, Vol. I., p. 744. 



seventh of an inch (the most favorable figures 

 to make for great relative depth of body), the 

 ratio will still be about four and one third. 

 This would appear to give a rather more 

 slender body than in typical inconsians, but 

 in reality it lies well within the range of 

 variation of inconsians as collected from al- 

 most any locality. 



In the course of making a collection of 

 Wisconsin fishes the State Geological and 

 Natural History Survey had occasion last 

 summer to send a collecting party under the 

 leadership of Mr. H. H. T. Jackson to the 

 Superior shore. Mr. Jackson was instructed 

 to keep a special lookout for sticklebacks in 

 those waters. As a result I have before me 

 various lots of sticklebacks collected from the 

 following places within the Lake Superior 

 Basin : Mamie Lake (Vilas County) ; Mon- 

 treal Eiver and Lake La Vine at Hurley 

 (Iron County) ; Siskiwit Eiver, Siskiwit Bay, 

 and Lost Creek Slough at Cornucopia, Flag 

 Eiver at Washburn, and Pike's Creek at Bay- 

 field (all in Bayfield County). 



Agassiz's specimens were taken at Michi- 

 picotin, on the northeastern shore of Lake 

 Superior, undoubtedly either in the lake itself 

 or very near it. There is no reason to sup- 

 pose that any form existing there would not 

 be found in other tributaries of the lake. 

 Such close restriction would be unique among 

 fishes of waters not landlocked. And more 

 especially must this force itself upon us when 

 we consider that Eucalia inconsians ranges 

 from Saskatchewan to Ohio, and Pygosteus 

 pungitius from France to Alaska, with only 

 a slightly modified form in Greenland. 



We feel justified therefore in believing that 

 if Eucalia inconsians pygmcea exists, speci- 

 mens of it would occur among our collections. 

 A careful examination of all our specimens 

 from Lake Superior discloses nothing that is 

 not typical inconsians. But an examination 

 of the few characters given for pygmcea 

 shows that these in themselves have no value. 

 Let us examine them separately. 



First, Size: — This is easily disposed of. 

 Any one who has had considerable experience 

 in field work among our common fishes knows 



