1893.1 



LITTLE-KNOWN EUEOPEAN VIPER. 



597 



Vipera boms, part., Camerano, Mon. Ofid. Vip. Ital., Mem. Ace. 

 Tor. (2) xxxix. 1888, p. 35, pi. i. figs. 16-18. 



Vipera bents, var. rakosiensis, Mt'hely, Zool. Anz. 1893, p. 190. 



Eye very small, its horizontal diameter not exceeding its 

 distance from the nostril, its vertical diameter not exceeding its 

 distance from the oral margin. 



The sha^je of the head, \vhich is smaller in proportion than in 

 V. berus, is remarkable for the somewhat pointed snont with its 

 very obtuse, although sometimes slightly raised, canthus. The 

 sincipital shields are constantly well developed, the frontal being 

 longer than usual in V. berus, its length considerably exceeding its 

 width, at least equalling its distance from the rostral, and usually 

 exceeding the length of the parietals ; the frontal is usually sepa- 

 rated from the supraocular by a narrow shield or a series of small 

 shields ; rostral as broad as deep, or slightly deeper than broad, its 

 tip in contact with a single small (apical) shield, very rarely with 

 two ; two canthal shields ; upper praeocular usually in contact with 

 the nasal ; a single series of scales betx^een the eye and the upper 

 labials ; sis to nine upper labials, usually seven or eight, third, 

 fourth, third and fourth, or fourth and fifth below the eye ; 

 usually only one labial, third or fourth, below the eye ; six to ten 

 scales round the eye, usually eight or nine. 



Scales in 19 rows, exceptionally 21 (21, exceptionally 19 or 23, 

 in V. berus), the dorsals narrower and more strongly keeled than 

 in V. berus; outer row perfectly smooth. 



Ventrals 120 to 135 in males, 125 to 142 in females. On 70 

 specimens of V. berus I find 137 to 148 ventrals in males, 135 

 to 155 in females. 



Snbcaudals 30 to 37 in males, 23 to 2S in females. In V. berus 



I find 33 to 41 shields in males, 26 to 35 in females. 



Length of tail 7 to 8 times in the total length in males, 9| to 



II times in females. 



The following are the measurements, in millimeties, and records 

 of the numbers of scales and shields in 40 specimens from 

 Laxenburg : — 



Sex. 



Total 

 Length. 



Length of 

 Tail. 



Scales. 



Ventrals. 



1 Caudals. 



6 



4l'U 



55 



19 



i;}.-) 



! 34 





4oa 



50 



19 



];jo 



i 33 





370 



50 



19 



129 



33 





370 



48 



21 



129 



1 y2 





350 



45 



19 



12!) 



32 





350 



45 



19 



120 



33 





330 



45 



19 



1.34 



30 





320 



40 



19 



131 



30 





295 



43 



19 



132 



34 





255 



37 



19 



1M2 



36 





240 



35 



19 



i;i2 



37 



" 



220 



.'«) 



19 



12(; 



3(1 



Puoc. Zool. Soc— 1893, No. XJj. 



40 



