MORPHOLOGY OF VENOMOUS SNAKES 11 



Homalopsis buccata. 



Scales in 37 to 47 rows. Ventrals 160 to 171; anal divided; subcaudals 70 to 

 90. Total length about 3 feet. Bengal (?), Burma, Indo-China, Malay Penin- 

 sula, Sumatra, Borneo, Java. 



Genus CERBERUS Cuvier. 

 Cerberus rhynchops and 2 other species. 



Genus HYPSIRHINA Wagler. 

 Hypsirhina plumbea and 14 other species. 



Genus HIPISTES Gray. 

 Hipistes hydrinus. 



Head covered with small scales, scales of body smooth, excepting the very nar- 

 row ventrals, which have double keels. Body laterally compressed, resembling 

 in general appearance the Hydrophinas. It is piscivorous and swims far out into 

 the sea. It inhabits Siam. 



Family COLUBRIDiE Boulenger. 

 PROTEROGLYPHA. 



Corresponds to Cope's two superfamilies Proteroglypha and Platycerca and Stejneger's Elapidas. 



This family contains all snakes with a permanently erect grooved poison fang 

 in the anterior portion of the horizontal maxillary bone. Boulenger and Stejneger 

 divide the members of this family into subfamilies Elapinae and Hydrophinse.' 

 As a rule, smaller, solid teeth are carried by the maxilla behind the grooved fangs. 

 Shape of pupil variable, some being round, some vertical. Elaps and Acanthophis 

 have vertical pupils, while the famous Cobra has a round one. Although their 

 poison apparatus is inferior to that of Viperidae in Boulenger's term or Solenoglypha 

 of the usual nomenclature, the Elapine snakes are the deadliest and often the most 

 dangerous of all snakes.^ Their general appearance is not essentially different 

 from that of most harmless colubrine snakes and the presence of the fang is the only 

 reliable difference in these species. Most Proteroglypha are viviparous, but the 

 famous cobra de capello and certain marine snakes are oviparous. Some are 

 terrestrial, others marine. 



The Elapine snakes are tropical. The whole Australian, Palaeotropical and 

 Neotropical regions, with exception of Madagascar and New Zealand, are inhabited 

 by them. They extend northward into the warmer parts of North Africa, and 

 range over a great part of the Palsearctic subregion, being found in North Africa 

 and southwestern Asia. They also inhabit the southeastern Asiatic islands and 

 mainland. 



Subfamily ELAPIN.^ Boulenger. 



All are terrestrial, and the general feature is that of the harmless colubrine snakes. 

 The comparatively small eye with vertical pupil, frequent absence of loreal, and 

 indistinctness in width of head and body are often of differential value in determin- 

 ing the species, but the presence of the grooved fangs is the last and reliable criterion. 

 The most remarkable feature of some of the Elapine snakes is that they can dilate 

 certain cervical ribs, assuming a hood-like or fan-formed shape when the snakes 

 are excited. This, together with the conditions of median dorsal scale rows and 

 subcaudals, serves to divide them into several genera. According to Cope the 

 presence or absence of a postfrontal bone draws the line between Naja and Elaps} 

 They live on small vertebrates: lizards, birds, rats, frogs, snakes, and occasionally 



1 Hydrinae Stejneger. 



*The most dreaded species are TVfl/a, O/" A//) /ja^M.^, and JSwwj^'arM^ in India, and Acanthophis and Pseu- 

 dechis in Australia. They all possess very powerful venom and have courage and are often 

 rapid in action. The OphipJiagus elaps of India reaches 12 feet and is the longest venomous 

 snake. 

 8 Cope gave them the rank of families, Najidae and Elapidae. 



