CROCODILIANS, LIZARDS, AND SNAKES. 

 Natrix comjjiessicauda walkerii I'aiToiv, 



983 



NATRIX COMPRESSICAUDA OBSCURA Lcennberg. 



Natrix compresaicauda ohacura Lcennbekg, Proc. U. S. Nat. Mus., XVII, 1894, 

 p. 330. 



I have not seen this form. It is thus described by Dr. Lcennberg: 



Scales in twenty-one rows. The color of the back is dark bluish gray, " soot 

 color." On this ground the three series of spots can scarcelj' be distinguished, 

 except on the anterior part of the body where they form transverse bands; the head 

 is too dark to show any postocular bands; upper and lower labials, as well as 

 mentals, with yellowish spots ; the ground color of the belly is gray, a little reddish. 

 On each side on the dorsal margin of the gastrosteges there is a small light spot; a 

 median black band extends from the first gastrosteges to the tip of the tail. On the 

 anterior part there is a yellowish spot on each gastrostege in this black band, and 

 the thirty anterior spots cover this band nearly completely, but farther back they 

 become smaller and less distinct, disappearing on the tail. 



From Key West, Florida. 



NATRIX COMPRESSICAUDA COMPSOL^EMA Cope. 

 Tropidonotus compsola'mns Cope, Proc. Acad. Nat. Sci. Phila., 1860, p. 368. 



Scales ill nineteen longitudinal rows, and keeled. Eostral plate 

 twice as broad as high. Prefrontals subtriangular; loreal longer than 

 high. One rather narrow jjreocular; postoculars three, the lowest 

 very small. Vertical and superciliaries elongate; lateral border of the 

 former scarcely converging; the latter narrow, Superior labials eight; 

 fourth and fifth entering the orbit. Inferior labials nine. Tail slender, 

 slightly compressed at the base, three-tenths of the total length. Gas- 

 trosteges, 126; a divided anal; urosteges, G7. 



Measurements. — Total length, 400 mm.; tail, 86 mm. 



Above, blackish brown, darkest anteriorly. Very indistinct pale 

 transverse bauds are apparent. They are irregularly oblique and sep- 

 arated by intervals of two or three scales wide. Superior and inferior 

 labials more or less completely margined anteriorly with yellow ; geneial 

 sind gular plates spotted irregularly with the same. (Jeneral color 

 beneath a peculiar stone brown. A darker shade occupies the center 

 of the gastrosteges as far as the vent. This is almost excluded ante- 

 riorly by a central series of transversely elliptical yellow spots, one near 

 tlie anterior border of each gastrostege. These become narrower and 

 broken, and upon the posterior two thirds of the belly are almost lost. 

 There is a very indistinct row of smaller spots upon each side of it 

 anteriorly. 



This species should be compared with A\f. sipedon and X. ralida. It 

 differs from the first in the numbers of rows of scales, and from all 

 three in the form of the muzzle and coloration of the lower surface. 



