124 



THE AMERICAN NATURALIST 



[Vol. XL 



statements are based, the literature has been carefully searched. 



If we turn to the earliest description, given by Schneider (1799, 

 p. 50) we read: "Corpus ultra 8 poUices longum." This 

 measurement was given for the specimen which he found in 

 Hellwig's cabinet at Braunschweig and which Hellwig had ob- 

 tained from Lake Champlain. The specimen described by 

 Lac^pede ('07, p. 230) was obtained by M. Rodrigues and placed 

 • in the Natural History Museum but its original source was un- 

 known. The specimen measured 15 cm. 



Mitchell ('21) in 1821 received a specimen from Major Dela- 

 field taken from Lake St. Clair. In a descriptive letter written 

 to Professor Configliacchi of Pavia we read the following: "He 

 grows, as I am informed, frequently to the length of two feet. 

 The present specimen is not more than one half that length, one 

 of the smaller having been selected for the greater ease of trans- 

 portation." 



A length of two feet is here mentioned for the first time, and 

 as Harlan ('35, p. 164) has already pointed out, this mistake was 

 due to the fact that Necturus and Cryptobranchus were confused 

 by IVIitchell. In a letter written to Charles de Schreiber in 1823 

 Mitchell ('21) even speaks of Necturus as the creature "which 

 the white fishermen have called by the vulgar name of Hell-bender 

 and the Indians Tweeg." It is not difficult to understand how 

 such an error might have occurred since certain naturalists (Daudin 

 Lacepede, Barton) had considered Necturus as the larval form of 

 Cryptobranchus. 



Even Cuvier ('29) writes: "L'espece la plus connue (Meno- 

 branchus) vit dans les lacs de 1 'America septentrionale, et devient 

 fort grande; atteint dit on, deux et trois pieds." Since this time 

 the error has been repeatedly copied. 



Cohration— The color of the adult is so variable that a descrip- 

 tion does little more than emphasize this fact; indeed the writer 

 has been so forcibly impressed with this variability that it has 

 led to the surmise that Necturus possesses the ability, more or 

 less common to other Amphibia, of changing its color through 

 its control of the black chromatophores. The animal usually 

 appears a dark ashy brown above, with more or less irregular 

 mottling; below it is more evenly colored and of an ashy flesh 



