166 MISS JOA^^ B. PROCTER ON THE 



A. E. Brown, in a paper in the Proc. Acad. Philad. 1893 

 (pp. 435-6), describes three species, but adds that he doubts their 

 right to more than a varietal distinction : — 1. Bothroj^s atrox, 

 described from two specimens from British Guiana; 196, 195 v., 

 42, 59 c, 27, 27 rows of scales, which are broad, with a high 

 short keel not extending to the tip. Abdomen unspotted. 

 2. B. lanceolaius, described from two specimens from Martinique; 

 199, 200 v., 69, 69 c, 25, 25 sc. Scales longer than in B. atrox, 

 and bearing a simple keel to the tip. 3, B.jararaca, described 

 from one specimen from. Brazil ; 206 v., 57 c, 27 sc. ; besides the 

 annulated markings, Mr. Brown notes that the canthus rostralis 

 is less sharp and the scales on the snout are larger than in the 

 preceding species, a fact which was also observed by Dumeril 

 and Bibron. 



G. A. Boulenger, Cat. Sn. vol. iii. 1896, pp. 535-537. 



Lachesis atrox. 161-216 v., 47-73 c. 



L. lanceolatus. 180-240 v., 46-70 e, 



Mr. Boulenger finds that the only distinctive character between 

 these species is that of scale-structure. In the former the scales 

 are "strongly keeled, the keels on the posterior part of the back 

 very high, swollen in the middle, and much shorter than the 

 scale." In the latter the scales are merely " sharply keeled," the 

 keel extending nearly to their extremity. He also describes the 

 ventrals of L. lanceolatus as yellowish, uniform, or powdered, or 

 spotted with brown, and in this respect many of the specimens 

 in the British Museum collection certainly disprove the state- 

 ment made by other authors, that the ventrals of this snake are 

 constantly immaculate. He adds that these species may have to 

 be united, as some specimens of L. lanceolatus "approach L. atrox 

 in the swelling of the scales at the base of the keels, and are thus 

 intermediate between the two species." Cophias jararaca and 

 Bothrops jararacussu ai'e placed in the synonymy of L. lanceo- 

 latus. 



V. Brazil, Def. contre I'Ophidisme (2nd ed, 1914), pp. 78, 84, 88. 



L. lanceolatus. 195-200 v., 50-53 c. Tropical America. 



L. atrox. 202 v., 55 c. Tropical America, less abundant than 

 the above in the southern states of Brazil. 



L. jararacugu. 170-176 v. Brazil (Sao Paulo and Rio). 



In describing the first two species Dr. Brazil maintains that 

 one of the main points of difierence between these snakes lies in 

 the " systeme de coloration " of L. atrox, of Avhich he says : " La 

 coloration du fond, sur lequel se dessinent des figures pareilles a 

 celles eonstatees dans I'espfece prc'cedente {L. lanceolatus) est d'un 

 gris rougeatre, parfois un ton gris cendre. Cette comhinaison de 

 coulears donne un aspect veloute a Vanimal, ce qui permet de le 

 reconnoitre a premiere mte." The ground-coloui> of L. lanceolatus 

 is described as " vert tres fonce, gris et quelquefois jaun^tre," 

 and the abdomen "vert fonce, parseme de taches jaunes," whilst 



