CROCODILIAN^, LIZAKDS. AND SNAKES. 1129 



Tlie (characters are in general like those of the typical S()lenojjly]»ha. 



The genera of Causithe are Ethiopian, except Azeiniopliis, which is 

 Indian, but has not been found out of Farther India. There are three 

 species of CauHus, and one each of the other genera. The African 

 genera are XaiotUm-Wke, in form, and of terrestrial habits, and the sih'- 

 cies of Cansns are generally distributed in Africa. None of the species 

 of the family reach a large size. 



VIPERID.E. 



I. Urostfges two-rowed. 



a. Apex of beiai])euis calyciilate. 



No Hounces; calyces deeply fringed Cipera Laiirt-iiti. 



" Nostral between iliree plates '' Giintber Dahoia Gray. 



No flounces, calyces moderately fringed; nostril surrounded 1>y scales and 



a supranasal; no supraocular nor nasal horns Bit is Gray. 



Flounced, spines below flounces; apex witb calyces not fringed; nostril sur- 

 rounded by scales and a supranasal. some of which are produced into 



boras Cloiho (iray. 



a a. Apex of heniipenis spinous. 



Nostril surrouiuled by scales and a nasal; born-like siqiraocular scales 



Cerasies Wagler. 



II. Urosteges one-iowed. 



Body and tail cylindrical . . . , EcMs Merreui. 



I5ody and tail compressed and prehensile Jiheris Cope, 



I am unacquainted with the penial structure of the last two genera. 



The ViperidiiP are restricted to tlie Old World; that is, to the Pale- 

 arctic, Paleotro]>ical, and Ethiopian regions. The genera are distrib- 

 uted as follows: 



Palearctic, 



Paleotropic.il. Ethiopian. 



Yiiiera Dnlioi.i Cerastes. 



r.itis. 

 Clotlio. 



Kcliis Efliis. 



Athens. 



The genera Vipera and Cerastes approach close to the con tines of the 

 Paleotropical in western Asia. Africa has the greatest number and 

 the jnost foiinidable s])eci('s. The best known are the i^uff adder. 7;///.s 

 arietaii.s, and the rliinoceros vipers, Clotlio rJiinocrros and ('. iiaKiconns. 

 These are large and brightly-colored snakes, of most dangerous char- 

 acter. The two Indian si)ecies are even better known for the fatalities 

 they occasion. These are the Dahoia russcllii, vv Ticpolonga, and the 

 Uchis c((riit<(f((. or Krait. The Daboia is a robust snake of medium 

 size, handsomely ornamented M'ith a pattern of large spots in brown 

 and yellow. The Krait is a veiy small snake of a light brown, with pale 

 spots and delicate lines marking the keels of the scales on the back. 

 By reason of its small size it is easily overlooked, and as it is extremely 

 venomous, it cau.ses many deaths in India. If makes a scraping or 

 rustling noise by folding itself and iubl)ing the scales of its body 



