34 PROCEEDINGS OF THE ACADEMY OF [Jan., 



Dark olive brown above, witli three light olive stripes, the dorsal 

 one three scales wide, and the lateral on the third, fourth and part 

 of the fifth rows; belly yellow in the middle and light olive on the 

 sides and outer row of scales ; an irregular clouded stripe of red- 

 dish brown on each side of the median yellow tract. Length 806 

 mm. (tail 168). 



Hab. — Western Louisiana and Texas. 



Tropidonotus compressicaudus Konnioott. 

 Proc. Acad. Phila., 1860, :J35. 



Size moderate; tail somewhat compressed; scales in 19 or 21 

 rows, very occasionally 23; oculars 1-3 (2); temporals 1-3 (2); 

 upper labials 8. The pattern in this species is not disiinct, and is 

 best seen in the young. The body color is greenish olive, with a 

 dorsal row of black spots and a smaller series on each side. The 

 spots are confused and irregular, the laterals being sometimes oppo- 

 site the dorsals and sometimes alternating with them ; they tend to 

 fuse together, forming cross-bands, which when they alternate, are 

 zigzag. The anterior spots in many specimens merge lengthwise 

 into more or less distinct stripes on the neck, which at times extend 

 some distance on the body. The belly is yellowish or ashy, com- 

 monly blotched with black, more heavily posteriorly; anteriorly 

 each ventral is margined with black, leaving a transverse elliptical 

 yellow mark in the centre, with sometimes a row of similarly 

 colored small spots on each end. Top of the head greenish olive, 

 often with an elongated black lilotch on the frontal and parietals ; 

 labials yellow, more or less margined with black. 



Two color forms may be distinguished : 

 Three rows of spots; traces of stripes on neck, 



1. T. c compressicaudus. 

 Cross-bands on body ; black stripes on neck, . . 2. T. c. iistus. 



Tropidonotus compressicaudus compressicaudus Kenn. 



Nerodia compressicaudci Kenu., Proc. Acad. Phila., 1860, 3.35; Natrix 

 compressicauda Cope, I. c, 669, and IJep. Nat. Mus., 979 ; T. com- 

 pressicaudus (part) Boul., I. c, I, 233. 



Grayish olive or ashy, with about forty dark spots on the back, 

 distinct but irregular; the dorsal and lateral series mostly alter- 

 nating, sometimes forming cross-bands in front. Indications of 

 short stripes on the neck. 



A small specimen collected by ]Mr. C. B. Moore, on Pine 

 Island, Charlotte Harbor, has 133 ventrals; 74 subcaudals; length 



