Vol. 5, p. 321)-332. September 15, 1930 



Occasional Papers 



OF THE 



Boston Society of Natural History. 



NEW SNAKES FROM COSTA RICA AND PANAMA. 

 BY EMMETT R. DUNN.^ 



While on Barro Colorado Island in July, 1930, Mr. James 

 Zetek showed me some snakes which he had taken on the Island 

 and in the neighborhood of Ancon. Among the latter was a 

 species of Sihynophis which seems new and remarkable. It may 

 be called 



Sibynophis zeteki, sp. nov. 



Type.- — Museum of Comparative Zoology no. 29060. 



Type locality. — Ancon, Canal Zone, Panama. 



Diagnosis.- — Close to S. venustissimus of Nicaragua and Costa Rica, but 

 with light instead of black snout, and with black rings in contact with the 

 red bands instead of light. 



Description. — Female: scales 17; ventrals 142; anal divided; caudals 65 +; 

 oculars 1-2; temporals 2-2; supralabials 8, infralabials 10; third, fourth, and 

 fifth supralabials in contact with eye; four infralabials in contact with anterior 

 chin shields which are much longer than those posteriorly; snout white; 

 black dots on the labials under the eye; parietals and nape black; black 

 dots on postoculars, temporals, and last labial; a light ring two scales long 

 followed by a black ring 13^ scales long back of nape; this followed by a red 

 band 9 scales long, the scales tipped with black; then black, yellow, black, 

 each ring two scales long; then red again, etc ; 12 red bands on body, varying 

 in length from 9 to 3 scales; tail with three broad red bands separated by three 

 black r.'ngs which in turn are separated by light rings; the combination about 

 equal to one red band, and being made up in about the proportion of 1 black, 

 1 yellow, 6 black, 1 yellow, 1 black; throat and belly light; a black dot on each 

 subcaudal; length 531 mm., tail 166 mm., imperfect. 



Remarks. — The arrangement of color bands in this species is 

 that of Lampropeltis, while the arrangement in S. venustissimus 

 is that of Micrurus. The scalation is scarcely different from 

 that of S. venustissimus. The type locality of iS. venustissimus 

 is Matagalpa, Nicaragua. I have also seen specimens from 



^ Contribution from the Department of Biology, Haverf ord College. No. 3. 



329 



