366 Illinois State Lahoratonj of Natural History. 



Length of body. 2.62; tail, 2.31. 



Southern Illinois, abundant. Makanda, Cobden, Anna, 

 Saratoga, W. Northfield (Yarrow). 



The head and ventral side of the tail are as a rule almost 

 or quite devoid of spots. Young examples generally have the 

 spots as numerous on the top of the head as elsewhere. The 

 margins of the vent are pale in the darkest examples. Under 

 stones and logs in southern Illinois this salamander is very 

 al^uudant. It sometimes occurs in caves. I have never seen 

 it in the water. Once disclosed, it is easily captured, as its 

 movements are not rapid. It has been reported common 

 throughout the State, l)ut occurs in lal)oratory collections made 

 in Union county only, though doubtless it is common in other 

 counties adjacent. 



Plethodon erythronotus, Green. Red-backed Salamander. 



Var. erythronota. 



Salamandra erythronota. Green, el our. Acad. Nat. Sci. Phila., 

 1818, 1., p. 356.— Harlan, .lour. Acad. Nat. Sci. Phila., 1876, 

 v., p. 329.— Storer, Bost. Jour. Nat. Hist., 1840, III., p. 53. 



Plethodon erythronota, Eaird, Jour. Acad. Nat. Sci. Phila.. '2d 

 Ser., 1849, I., p. 285. 



Plethodon erythronotus, var erythronotus, Cope, Pro3. Acad. 

 Nat. Sci." Phila., 1869, pp. 99, 100. 



Plethodon chiereus, subsp. erythronotus, Davis and Rice, Bull. 

 III. State Lab. Nat. Hist., I., No. .5,1883, p. 12; Bull. Chicago 

 Acad. Sci., 1883. 



Var. cinerea. 



Salamandra cinerea, Green, Jour. Acad. Nat. Sci. Phila., 1818, f., 



p. 326.— Harlan, Jour. Acad. Nat. Sji., Phila., ISI^B. V., 



p. 330. 

 Plethodon (-inercus. Baird, .lour. Acad. Na^.. Sci. Phila., 2d Ser., 



1849, I., p. 285. 

 Plethodon erythronotus, var. clnereus. Cope, Proc. Acnd. Nat. 



Sci. Phila., 1869, p. luO. 

 Plethodon duereus, subsp. duereus, Davis and Kice. Bull. Ill 



State Lab. Nat. Hist., I., No. 5, 18s3, p. 12; Bull. (Miicago 



Acad. Sci., 1883. 

 Salauiirndra erythronota, l)e Kay, Nat. Hist. N. V., 1., Zool. III., 



Kept, and Amph., 1842, p. 75, pi. 16, Hg. 38. 



