132 



two and three respectively. In No. 18,818, however, the pre- 

 oculars are three on the right side and two on the left and the 

 scale rows are 21; while in No. 18,812 the scale-rows are 19 in 

 number, and but two preoculars are present. There seems no 

 reason therefore to continue to recognize T. mocquardi as valid. 



This is one of the very few neotropical species that frequent 

 salt water. It is found about mangrove swamps, if not exclusively, 

 at least frequently, having much the habits of Matrix compressi- 

 cauda. 



Pseudoboa petola (Linn^). 

 Cohiher petola Linne, Syst. Nat., ed. 10, vol. 1, p. 225, 1758. 



This wide-ranging species is apparently rare in Panama al- 

 though common throughout most of its enormous range. It is 

 represented in our collection by several specimens from Ancon, 

 Canal Zone, taken by Mr. James Zetek, of the U. S. Department 

 of Agriculture, and others. The Harvard party in Panama during 

 1924, as during other trips, is much indebted to Mr. Zetek for 

 very many favors. 



Micrurus dunni Barbour. 



No. 18,813, Museum of Comparative Zoology, from near 

 Corozal, Canal Zone. This is the second recorded example of 

 this species. It is much larger than the type, being 350 milli- 

 meters long, the tail 26 mm. in length, thus nearly double the 

 length of the original specimen (Occ. Papers, Mus. Zool, Univ. 

 Michigan, no. 129, p. 15, January 25, 1923). That snake was de- 

 scribed as having the third and fourth upper labials nearly equal in 

 size but the second example shows that the third labial in the adult 

 is much larger than the fourth. This agrees with the condition 

 in the closely allied forms such as M. lemniscatus, M. filiformis 

 and M, hollandi. This specimen has nine triads of rings as against 

 eleven in the type. 



