224 DR. H. GADOW ON MEXICAN [June 6, 



southern half; coloured and behaving exactly like Elaps, it is 

 often mistaken for a true " Coralillo." 



Urotlieca, Dromicus, Drymohms, and Leptophis are mainly 

 Central and South American with species in the Antilles, extend- 

 ing northwards into the Atlantic and Pacific Tierra Caliente, on 

 the east side even into Texas. Drymohms margaritiferus is the 

 commonest tree-snake. D. hoddaerti ranges from South America, 

 Trinidad and S. Vincent, and on the Pacific side it has been 

 brought from Tres Marias Islands. 



Rhadinea is South and Central American, going into Mexico 

 east and west and onto the slopes of the Southern plateau. 

 Urotheca likewise Central and South American and Cuban ; 

 U. elajjoides from Costa Rica along the Atlantic side to Orizaba. 



AStreptophoriis typically Central American, extending into the 

 Atlantic Tierra Caliente. S. diadematiis from Tabasco through 

 Oaxaca to Jalapa and Orizaba, S. atratus from Ecuador and 

 Venezuela to Jalapa. ISTone is Antillean. 



Hyp)siglena torquata from Venezuela to California, in Mexico on 

 the plateau and the Pacific side. 



Atractes, Tropidodipsas^ Dirosema, and Geop>his are Southern 

 genera, extending into the Atlantic and Pacific Tierra Caliente, 

 the last genus with more western range. G. {Geagras) ridAmita 

 I have found in the sand-dunes of the lagoons near Tehuantepec. 



Opisthoglypha. — IVimorphodon, a Mexican genus with western 

 preference. T. upsilon extending northwards into Arizona, south- 

 wards to Panama ; T. hiscutatus distinctly Pacific from Mazatlan 

 to Panama ; T. tau on the Isthmus of Tehuantepec. 



Himantodes, a typical Neotropical forest genus, of which H. 

 cenchoa has spread into the Atlantic, H. gemmistrata and 

 H. tenuissima into the Pacific Tierra Caliente. Cope's statement 

 that H. gemmistrata has been found at Toluca seems to be 

 erroneous. 



These Tree-snakes are called " Suchil " in Oaxaca and on the 

 Isthmus, are feared as poisonous, and are said to attain a very 

 great length. Every snake, when in motion, appears to be much 

 longer than it is, and these active creatures gliding rapidly through 

 the dense canopy of a tropical forest seem indeed to give one the 

 impression of prodigious length. Another name for Tree-snakes 

 is " Bejuquillo," in allvTsion to lianas, which are called bejuco. 



Lep)todira, ISTeotropical, into the eastern and western Tierra 

 Caliente, remaining outside the plateau, although L. albofusca, 

 which extends to Para and Ecuador, ascends outlying mountains, 

 like the Nevado de Colima, up to 7000 feet. L. septentrionalis, as 

 the most northern oflfshoot, occurs in Texas and New Mexico. 



OxyrhojnijS, essentially South and Central American ; 0. cloelia 

 and O.plumheus stop at the Isthmus of Tehuantepec ; 0.petiolari%is 

 goes into Guerrero. This genus is of special interest since it 

 contains the only Opisthoglyph which has reached the Antilles, 

 but only the Lesser. 



