136 BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



exhibits a very fiue mottling of brownish, scarcely obscuriDg the effect 

 of the red grouud. The mottling is sometimes equally distributed — 

 sometimes concentrated in some places more than others. The sides of 

 the body are abruptly and continuously dark brown, but soon fades off 

 below into the pepper and salt of the lower sid^s and belly. There is 

 sometimes the effect of a broad dark stripe on each side the red, but 

 this is usually very illy defined below. 



The color of the red stripe varies considerably. Sometimes it has a 

 shade of pink— sometimes of orange or yellowish. The close resem- 



4- 3 Q 



Fig. 30. Plethodon cinereiis erythronotus, 4828. St. Catharines, Canada; f. 



blance in size and character with the frequent association in the same 

 localities between the two species have given rise to the belief that they 

 were different sexes of the same species. That this supposition is in- 

 correct is proved by the fact that both males and females are found of 

 each kind, as was long ago noticed by Haldeman. As varieties they 

 are very permanent ones, as I have found all the young of the same 

 brooil or set of eggs, whether in the eggs or just escaped from them, 

 uniformly with either dark backs or red ones. I have found adult red- 

 backed specimens watching eggs with red- backed embryos, and brown- 

 backed in charge of brown-backed embryos. There is also some differ- 

 ence in geographical distribution. Thus, on the west side of Lake 

 Charaplain, in Essex County, New York, Professor Baird states that he 

 has found the red-backed salamander very common, and never saw there 

 the P. cinereus. Among a very great number of specimens which I have 

 examined in the collections of the Smithsonian Institution, the Acad- 

 emy of IsTatural Sciences, and Essex Institute I have observed but four 

 specimens of the red-banded variety and four of the gray which could 

 be regarded as intermediate in character. This appears in a rufous 

 cast in the dorsal color of the latter and a slight obliteration of the 

 borders of the dorsal baud in the former. Such coloration is, however, 

 very uncommon in the living animal, which is everywhere exceedingly^ 

 abundant. The statement made by J. A. Allen that such are abundant 

 in Massachusetts is not confirmed by the specimens in the museum of 

 the Essex Institute, Massachusetts. 



An examination of the types of Dr. Sager's Salamandra agilis (3770) 

 shows them to belong to this subspecies. His variet^^ with livid back, 

 is the Plethodon cinereus cinereus. 



