Both snakes were obtained from trees when they were felled. In life the dorsum was pinkish orange with dark chocolate brown blotches narrowly edged with black. =Sibon nebulata nebulata= (Linnaeus) 20 km. NW of Chinajá, 1. This specimen, a male having a body length of 544 mm. and a tail length of 198 mm., was found in a felled tree. In life the belly was pink and black; the dorsal black blotches were narrowly outlined with pink. =Spilotes pullatus mexicanus= (Laurenti) Chinajá, 3; 20 km. NNW of Chinajá, 1; Sayaxché, 1. This large snake, locally called _mica_, seems to be equally at home on the ground and in low trees and bushes. It is fast moving for a large snake; two individuals escaped capture. The natives said that this snake eats other snakes, but examination of stomachs revealed no supporting evidence. =Stenorrhina degenhardti= (Berthold) Chinajá, 1. This specimen, a female having 158 ventrals, 37 caudals, and a total length of 489 mm., was found on the forest floor. On the olive-brown dorsum are 27 irregular, narrow, dark brown, transverse bands. The head is uniform olive-brown; the chin and labials are cream-color. The venter is cream-color with a row of brown spots forming a midventral stripe. A large spider was found in the stomach. I have refrained from assigning a subspecific name to this snake. Cursory examination of specimens from throughout México and Central America reveals a bewildering array of variation in coloration that suggests that the subspecies _mexicanus_ is not recognizable, or that two species occur sympatrically in parts of southern México and northern Central America. =Tretanorhinus nigroluteus lateralis= Bocourt Chinajá, 1. A single male having 136 ventrals, 75 caudals, and a total length of 407 mm. was found by a stream in camp. The dorsum is pale grayish tan with 34 pairs of small chocolate brown spots, some of the anterior ones of which are connected across the back. A cream-colored lateral stripe is on the third and fourth dorsal scale-rows anteriorly and the second and third rows posteriorly. The lower dorsal scale rows are black. The venter is dark grayish brown with cream-colored flecks anteriorly and creamy gray posteriorly where the dark color is restricted to the midventral region and the lateral edges of ventrals and first dorsal scale-row. =Xenodon rabdocephalus mexicanus= Smith Chinajá, 1; 20 km. NNW of Chinajá, 1. Both individuals were found on the forest floor. An adult male having a total length of 420 mm. has a cream-colored venter with brown flecks. A juvenile having a total length of 172 mm. has a creamy white belly with black crossbands. At the suggestion of L. C. Stuart, I am following Schmidt (1941:501) in placing _X. mexicanus_ as a subspecies of _X. rabdocephalus_. =Micrurus affinis apiatus= (Jan) 20 km. NNW of Chinajá, 2; Sayaxché, 1.