Poisonous Snakes of the World 



KEY TO GENERA (Continued) 



Is. A. \'t'nlials with i;iict;ii i<t'cl : suIxmikIiiIs |)iiiri'(l C'eranten 



11. N'i'iit lal^ roiiiidi'd ; siilx'iiiKlal.s siiif^li- Kchis 



1'.". .V. K()>lial ill coiitiicl witli iiasiil, or scpaialcd from it. by ii 



siiiij;li' lar<ii> sciile Vlpera 



Ii. Koslral scparalcil frnni iia^al \>y I or hkhc iows of 



siiiali scales I' it in* 



'H. worlhinytuni, with tlie iinsal In coiitnct with rostral, single Hubcuudulx, unil lateral keels 

 on the ventrals. will not key out properly. 



GENERIC AND SPECIES DESCRIPTIONS 



COLUBRIDAE: Genus Dupholidus Duvernoy, 1832. 

 1 '>ooiii-.iaiiij. 



A .single species, />. Iiiim.i Smith. Tlii.s snake, found 

 only in troiiical and smillicrn .Vfrica. i.s the iiinst daii- 

 Keroiis iiieinlitM' of tlie family Culiiliridac. 



Dc/iiiitioii: Head oval but distiiict from slender iiecU ; 

 crown of head convex. Snout short with a distinct 

 lanlhus. Hddy slender and elon),'are. moderately com- 

 Iiressed ; tail long and slender. 



Eyes very large; pupils round. 



Head scales: The usual 9 on the crown. Laterally, 

 a single loreal scale separates the nasal from the one 

 or two preoculars. 



Rody scales: Dorsals narrow, distinilly keeled, and 

 with apical pits; in IT-lil oblique rows at niidbody, 

 more (21-2.")) anteriorly, fewer (1.3) posteriorly. Ven- 

 trals of normal size, obtusely angulate laterally, 164-201 ; 

 anal plate divided (Like most "present or absent" 

 scale characteristics, this is not true 100 percent of the 

 time: the anal plate is rarely entire. The question of 

 identitication of a boonislang with an entire anal plate 

 caused the death of a noted herpetologist, Karl P. 

 Schmidt, in lO.'u. Srr Pope. 1!).">8) : suhcaudals paired. 

 87-131. 



JIaxillary teeth : A series of 7-s small subeiiual teeth 

 followed, after a short interspace, by .S very long grooved 

 fangs. 



Boomslang, Dixplwlidiis tyinix Sniitli. 



Iilciitiflcutiiiii: The boomslang does not look much 

 different from many other tree-dwelling snakes which 

 inhabit its range and. of cimrse, it is not always in a 

 tree. However, the innocuous green bush snakes (Pliiln- 

 /Iiamniis) have smooth scales, and keeled and notched 

 ventrals. while the dangerous inambas ( Deiirlroas-iiis) 

 have a much longer and narrower head, lack a loreal 

 scale, and have smaller eyes. Adult boomslangs average 

 4 to .") feet, with the record length being "a little over 

 feet." 



Color varies from almost black to almost unicolor 

 green : no blotches or distinct spots. Individual dorsal 

 scales may be yellow, brown, or green, often with black 

 on the margins. Ventrals black to greenish white, de- 



licnding on dorsal c<j|or. Xo dislinci head pattern. 



DislriliKlidii: Open savaniuih and brushy country 

 throughout tropical aiul southern Africa; not found in 



Figure ."i.3. Uoomslang, Displidlhlns- itiptis. Photo by 

 Roy I'inney and National Zoo. 'Washington, D.C. (See 

 also plate VII, figures 1, 4; plate VIII, figure 2.) 



rain forest regions nor in true desert. 



Rciiiarls: This snake is not aggressive and will 

 (luirkly make for the nearest tree or bu.sh if surprised 

 on the ground. In its arboreal habitat it disappears 

 quickly. However, if cornered or restrained, it inflates 

 its neck to more than double its normal dimensions. 

 This exposes the skin between the scales of that region, 

 which is often brightly colored. If its bluff is unsuc- 

 cessful, the boomslang will bite. 



Although it is a rearfanged colubrid snake, the boom- 

 slang has relatively long fangs and its venom, though in 

 small quantities, is more toxic, drop-for-drop, than that 

 of African cobras and vipers. The venom cau.ses severe 

 internal bleeding ; every mucous mend)rane may ooze 

 blood: a luimber of deaths have been reported. (Pope, 

 IO.jS.) 



90 



