REPTILES. 87 



26 (Riithven, 1006, 111) for an Isle Rovale, Michigan, specimen. 



Range: The species lias been reported from: Michigan (Miles, 

 1S61, 233), Ann Arbor (Smith, 1879, 7), Porcupine Mountains, On- 

 tonagon County (Kuthven, IDOla, 189, 191), Isle Koyale, Porcupine 

 Mountains and Kalamazoo County (Clark, 1905, 109), Porcupine 

 Mountains, Iron Countj^ Marquette and Isle Royale (Ruthven, 1906, 

 110, 111), Isle Royale (Ruthven, 1909, 332), Sand Point, Huron 

 County (Ruthven, 1911a, 267). The writer has seen specimens 

 from the following localities : Ann Arbor, Washtenaw County, 

 Iron River and Crj-stal Falls, Iron County, Iron Mountain and 

 Brown Lake, Dickinson County, Isle Royale, Keweenaw County, 

 Porcupine Mountains, Ontonagon County, Marquette, Marquette 

 County, Plainfield, Livingston County, Sand Point, Huron County, 

 Hancock, Houghton County, Alma, Gratiot County and Dr. F. N. 

 Notestein informs the writer that he saw it in Otsego County in 

 1911. 



HETERODON PL.ATYRHINUS Latreille. 



HOG-NOSED SNAKE. 

 (PI. IX b.) 



Coluher heterodori, Sager, 1839, 302. 



Hetcrodon platijrliiniis, Smith, 1879, 6. Clark, 1905, 110. Notes- 

 stein, 1905, 118. Ruthven, 1909a, 117; 1911a, 265. Thomp- 

 son, 1911, 107. 

 Heterodon platyrliinus niger. Smith, 1879, 6. 



Description: A snake of robust build occasionally attaining the 

 length of three feet, but usually about twenty-eight inches. Head 

 short and rather broad. The rostral plate greatly developed and 

 protruded upward and forward, projecting from the muzzle as the 

 apex of a triangular pyramid; the anterior face broad and flat, the 

 laterals slightly concave so that the lateral and dorsal edges are 

 projecting. Internasals entirely, and prefrontals partially, sepa- 

 rated by a narrow and elongated plate (azygous) having the form 

 of an irregular pentagon whose sides are parallel. The azygous with 

 more or less of a median keel (continuing from the dorsal edge of 

 the rostral). Two large temporal scales bordering the last three 

 supralabials and separated from the temporals by two or three rows 

 of smaller scales. A single loreal, and two nasal plates, the nostril 

 valvular and situated entirely in the postnasal. A single and con- 

 tinuous series of small plates (9, 10, 11, or 12 in number) border- 

 ing the eye on the anterior, posterior and inferior sides, occupying 

 the place of the usual preoculars and postoculars, and separating 

 the orbit from the supralabials. 



