236 BULLETIN OF THE 



Baird's detailed description of the exterior characters of E. epixanthus is 

 in every respect applicable to fully one half the specimens from Maine re- 

 ferred to above, while none differ essentially from it. The differences 

 referred to by him in the relative length of the nasals in the two sup- 

 posed species are relatively very slight, especially as compared with the 

 large amount of variability presented in a large series of the skulls of 

 Arctomys monax, or of our common squirrels or rabbits; the difference 

 in the proportional length of the nasals to the whole length of the skull, 

 in five specimens of E. epixanthus and three of E. dorsatus, as given by 

 Professor Baird, being but 1 per cent; the nasals in E. dorsatus being 37 

 per cent of the whole length of the skull, and in E. epixanthus 41. In 

 No. G76 (E. "dorsatus") of Baird's table, the proportional length of the 

 nasals to the entire skull is 39 per cent; in No. 3066, 32 per cent. In 

 No. 822 (E. " epixanthus " ), 39 per cent. In other words, the specimen in 

 the series of E. dorsatus in which the nasals are longest differs less than 

 one-third of one per cent in the proportional length of the nasals to the 

 whole skull from the specimen with relatively the shortest nasals in the 

 seies of the E. epixanthus specimens. 



I am not able at this time to refer to M. Brandt's paper, but Water- 

 house, in his Natural History of the Mammalia,* refers to it as follows : 

 " Five specimens of an Erethizon from the West Coast of North America, 

 in the Museum of St. Petersburg, having the exposed ends of the longest 

 hairs of the fur of a brownish-yellow color instead of white, as the same 

 hairs are stated to be in the E. dorsatus, M. Brandt is inclined to sup- 

 pose there are two species of Erethizon, but not having specimens of the 

 Canada animal for comparison, he is not able to satisfy himself upon 

 this point. The specimens examined by M. Brandt are from California 

 and Unalaska, and I may add that a similar specimen is found at Sitka, as 

 I remember to have seen a specimen in the Leyden Museum from there 

 agreeing with M. Brandt's description ; its spines [not hairs] were most of 

 them of a delicate yellow below the dark point." The following is Mr. 

 Waterhouse's description of E. epixanthus, compiled from M. Brandt's me- 

 moir : " The longer and coarser hairs brownish-yellow at the point ; spines 

 white or yellowish at the base, and most of them brownish-black or dusky 

 at the apex." 



It hence appears that the three principal writers on the subject — Brandt, 

 Waterhouse, and Baird — have neither of them had specimens of the two 

 species for comparison at the time of writing; Brandt having only his 

 five West Coast specimens, Waterhouse compiling from Brandt, and 

 Baird's specimens coming, two from the Republican Fork, one from New 

 Mexico, and one from California, with three or four skulls from the East. 



* Vol. II, p. 442. 



