SNAKES OF THE GENUS PITUOPHIS 55 



for the Florida form. As corrected and published it is very typical of the Carolina 

 forms. * * * Holbrook's was the first good description, and it seemed wise on 

 this basis to establish the type locality. 



Diagnosis. — This form may be distinguished from its allies, m. 

 mugitus, m. lodingi, and m. ruthveni, by the coloration. While 

 mugitus is pied rusty brown or red, and white, lodingi is uniformly 

 black above and slate-gray below, and ruthveni is brown with darker 

 brown spots, melanoleucus is distinctly black and white. It may be 

 separated readily from lineaticollis, deppei, and jani by the presence 

 of four, rather than two, prefrontals, by the entrance of a single 

 supralabial into the eye on either side, instead of two, and by the 

 shape of the rostral, which is at least twice as long as broad in melano- 

 leucus, while it is as broad as or broader than long in the three forms 

 of the deppei group. It may be distinguished from all other forms 

 of the genus also by the higher rostral, since it is never twice as long 

 as broad in the latter forms, and in addition by the smaller number of 

 spots (30 to 37 in melanoleucus as opposed to more than 40 in all of 

 the other forms under consideration). 



Description. — The body is stout, with the snout rather pointed. 

 Owing to the great elongation of the rostral, the upper jaw protrudes 

 somewhat beyond the lower. The tail length is 0.120 to 0.141 of the 

 total length (average 0.131). The longest specimen examined meas- 

 ured 1,980 mm. in length. Engelhardt (1916, p. 7) records a specimen 

 that "at the time of capture was said to have measured seven feet, four 

 inches. Actual measurement shows a total of six feet and nine inches, 

 but it is possible that on account of mutilation in the killing, part of 

 the skin was rendered useless, for the head and neck, for a length of 

 eight inches, have been preserved separately." 



The commonest dorsal scale formula is 27-29-21; the number of 

 dorsal scales varies, however, from 25 to 29 on the neck, from 27 to 

 31 in the middle of the body, and from 19 to 23 just anterior to the 

 vent. The other scale characters are as follows: Ventrals normally 

 205 to 223 (average 214.6), 249 in one aberrant specimen; caudals 

 52 to 66 (average 58.2); supralabials 6 to 9, usually 8 (average 7.9) the 

 fourth usually, third or fifth occasionally, entering the eye on either 

 side; infralabials 10 to 13, most often 12 (average 12.2); preoculars 

 generally single, rarely 2; postoculars 2 to 4, generally 3; loreal usually 

 present; no azygos; rostral long and narrow, at least twice as long as 

 broad, and penetrating at least one-half the distance between the 

 internasals; frontal divided for as much as one-half of its length, or 

 undivided. 



The dentition is as follows: Mandibular teeth 17, decreasing slightly 

 in size posteriorly; maxillaiy teeth 16 to 17, decreasing slightly in size 

 posteriorly; palatines 9 to 12, subequal, smaller than mandibular and 

 maxillary teeth; pterygoids 6 to 8, smaller than palatines, and decreas- 

 ing slightly in size posteriorly. 



