CROCODILTANy, LIZARDS, AND SNAKES. 867 



Scales weakly keeleil, lirst on tenth row; rostral little prouiiuent, not narrowed 

 above; bead Hat; bead stripes present ; spots numerous, 36-79 on body. F. catcnifer 



Scales weakly keeled, beginning on tenth row; rostral plate not narrowed, and lit- 

 tle prominent: head Hat; spots few, 40-44 on body; anteriorly red; no head 

 strjijes P, veriehralis. 



The head stripes consist of a band extending from the eye to the 

 angle of the mouth; another from the eye to the uiiper lip below it, and 

 another connecting the orbits across the front of the frontal plate. 

 These stripes are present in the young of the species, which lack them at 

 maturity. The increase in the number of spots is accomplished by the 

 division of those on the posterior part of the body. 



The number of the labial plates is apt to be unequal on the opposite 

 side. Thus in seventy-two specimens examined, flfteen have nine 

 labials on one side and eight on the other. The P. catenifer displays 

 the greatest irregularity in this respect, six out of sixteen specimens 

 having labials S-9. 



PITYOPHIS MELANOLEUCUS Daudin. 



Pityophis melanolencus Holhrook, N. Amer. Herpt., IV, 1842, p. 7, pi. i. — Baird 



and GiRARD, N. Amer. Kept., Pt. 1, Serp., 1853, p. 65. — Dumeril and Biurox, 



Erp. Gc<n., 1854, VII, p. 233.— GiiNTHP:R, Cat. Col. Serp. Brit. Mus., 1858, p. 



86.— Cope, Check-list N. Amer. Batr. Kept., p. 39; Bull. U. S. Nat. Mus., No. 1, 



1875, p. 39. 

 Coluber melanoleucus Daudin, Hist. Kept., ^ I, 1803, p. 409 (from Bartram). — 



Harlax, Journ. Acad. Nat. Sci. Phila., 1827, p. 359. 

 Coluber melanoleucus Daudin, Hist. Nat. Kept., VI, 1799, p. 409. — Harlan, Journ. 



Acad. Nat. Sci. Phila., V, 1827, p. 359; Med. and Phys. Res., 1835, p. 122.— 



BouLENGER, Cat. Snakes Brit. Mus., II, 1894, p. 68. 



Head ovoid, broad behind. Anteorbital one; postorbitals three. 

 Dorsal rows of scales twenty-seven to thirty-one, the four outer rows 

 smooth, fifth, sixth, and seventh with an obsolete keel. Tail about one- 

 seventh of total length. Head spotted with black. Color of the body 

 whitish, with a dorsal series of very large blotches, the twenty-fourth 

 to thirtieth opposite the aims; anteriorly and posteriorly eraarginated 

 on the anterior third of the body; oblong posteriorly. Elongated 

 smaller blotches on the flanks, forming three indistiiict series, often 

 conlluent. Abdomen unicolor. A series of twenty-seven to thirty 

 distinct blotches along the extremities of the scutelhc. 



Head robust, conical. Frontal plate sub[)entagonal, broad anteriorly. 

 Parietals a little larger than the frontal, and as broad anteriorly as long. 

 Internal postfrontals elongated and subtriangular ; external postfrontals 

 liolygonal. Prefrontals quadrilateral, separated by the rostral. fJos- 

 tral narrow, very convex, raised above the surface of the snout, and 

 reaching the prefrontals. Nasals very large, anterior one the larger. 

 Nostrils vertically oblong, situated in the middle and between both 

 plates. Loreal ovoid, small, horizontal. One large anteorbital, with its 

 anterior margin convex, of the same width above as below. Three 

 postorbitals, proportionally large. Temporal shields small, three or 



