Poisonous Snolces of ihe World 



III llic siiiillit'l'li piil'l i>t' III)- Al'illililli I'l-liilisiilii IIS well ii> 

 lliroimh iiiiii'li uf nurt Ill-Ill ami rciilnil Afrini). All ari' 

 small smikt's, Irss lliaii .'I feet In li-iinlli. Ilowfvi'r. tlii-y 

 have larm- faims (wlilili look i-iiorim>iis In tlioir small 

 moiillisi and art- capalili' of inlliitliiK st-riotiH Mies l<> 

 tlinst- picking llicm up or sU-ppliiK on tlicni with liari> 

 rict (sw p. l>!»). 



Drfttiitiiin: Head short and conical, iiol distinct from 

 nt-ck. no canthiis; snout hroatl. Ilallfncd. often pointed. 

 llody cylindrical, slendfr in small individuals, stmit in 

 laritK ones; tail short. I'lidin;; in a disliiict spine. 



Kyes very small ; impils round. 



Head scales: The usual D crown scales, rostral en- 

 larged, extendiii); lietweeii Interna.snls to some degree, 

 often pointeil ; frontal large and broad, supraoculars 

 small. Laterally, nasal in contact with single preocular 

 (no loreal). usually one postocnlar. 



Hody scales: Dorsals smooth willmui apical pits, in 

 r.>-.'?7 nonohliipie rows at midtioily. \eiitrals ITS .'?7<t: 

 anal plate entire or divided (the <inly viperid snake willi 

 divided anal plates I ; sulicaudals single or paired, IS ,'!!). 



VIPERIDAE: Genus Bitis Gray, 1842. 



A I 



iicaii \ ipiTS. 



Ten speeies are found in tropical and southern Africa. 

 They include the largest of the true vii)ers (Viperidae) 

 as well as some small and moderately sized ones; all 

 of the memhers of the genus are dangerous, some of 

 them exeremly so. The puff adder, liitix iirirtdnx. is 

 found widely thnnigli the region (see ii. 101 ). 



Definition: Head broad and very distinct from nar- 

 row neck ; snovit short, a distinct canthus. Body some- 

 what depressed, moderately to extremely stout; tail 

 short. 



Eyes small ; pupils vertically elliptical. 



Head scales : No enlarged plate.s on crown, covered 

 with small scales. Some species have enlarged and erect 

 scales on snout or above eye. Laterally, rostral sepa- 

 rated from nasal by (in Ii. irnrtliinf;toni) to 6 (in 

 some Ii. nii-^iirornis) rows of small scales, eye separated 

 from supralahials by 2-."> rows of small scales. 



Body scales : Dorsals keeled with apical pits, in 21- 

 40 nonoblique or slightly oblique rows at midbody, fewer 

 anteriorly and posteriorly. Ventrals rounded or with 

 faint lateral keels, 112-1.J.3 ; sulicaudals paired, laterally 

 keeled in some species, 16-37. 



VIPERIDAE: Genus Cousus Wagler, 1830. 



Night udders. 



Four .species are found in troiiical and southern Africa. 

 None attains a length of over 3 feet. The fangs are 

 relatively small, and the venom is rather mildly toxic. 

 They look surprisingly like nonpoisonous snakes. Night 

 adders are not considered dangerous to life but their 

 bite is painful and venomous. The rhombic night ad- 

 der. C. rlioDibcatns, enters the southern part of this re- 

 gion (p. 102). 



lUfinitiiin: Head inoderale Iti size, fairly distinct 

 from neck, an obtuse ciinlhus. Itody cylindrical or 

 slightly depressed, moderately slender; tail short. 



Kyes moderate In size; pupils round. 



Mead sciiles: The usual '.I cinw a scales; rostral 

 broad, sometimes pointed and upturned; frontal long. 

 suprnoculars large. Laterally, a loreal present, separat- 

 ing nasal and iM-eo<'ulars ; siiboculars lu-eseut, separating 

 eye from labials. 



Body scales: Dorsals smooth or weakly keeled, with 

 apical pits, In l.')-22 ohlhpie rows at midbody, fewer 

 (11-14) posteriorly. Ventrals roundcil. KM) l.'i.'i; sub- 

 caudals single or paired, 10-.33. 



VIPERIDAE: Genus Cerastes Laurenti, 1768. 



il 



IIIIKmI \l|ICfS. 



Two species are recognized; both are restricted to the 

 desert regions of northern Africa and western Asia. 

 Xeither is a large species; I lie bite is painful but usually 

 not serious. 



Definition: Head broad, flattened, very distinct from 

 neck ; snout very short and broad, canthus indistinct. 

 Body depressed, tapered, moderately slender to stout; 

 tail short. 



Eyes small to iiKJderate in size; jiupils vertically el- 

 lilitii'al. 



Head scales: Head covered with small irregiUar. 

 tubercularl.v-keeled scales; a large erect, ribbed horn- 

 like scale often present above the eye; no other enlarged 

 scales on crown. Laterally, nasal separated from rostral 

 by 1-3 rows of small scales; eye separated from supra- 

 laliials by .S-r> rows of small scales. 



Body scales : Dorsals with apical pits, large and 

 heavily keeled on back, smaller laterall.v, oblique, with 

 serrated keels, in 2.3-3."> rows at midbody. A'entrals 

 with lateral keel. 102-1(>.T ; subcaudals keeled posteriorly, 

 all paired, 18-12. 



African Desert Horneid Viper, Cerctfttes cerastes 

 (Liiiiiiieus). 

 niriitifieatioii : Many individuals of this species have 







Sefi-Wt 





Figure 51. — African Desert Horned Viper, Cerastes 

 cerastes. Photo by Zoological Society of San Diego. 



82 



