152 ON THE BATRACHIA AND REPTILIA OF COSTA RICA. 



123. Lachesis stenophrys, Cope, sp. nov. 



Scales in thirty-six longitudinal series, of which ten on each side of the median 

 line support a central tubercle. The muzzle is short and depressed, and the 

 rostral plate is an equilateral triangle. The superior labials number nine, of which 

 the third is much the largest. The second is low, and does not bound the maxil- 

 lary pit. The latter is bordered by three scuta ; the superior narrow, bounds the 

 two preoculars ; the inferior wider, stands on the third labial, and the anterior, 

 which is subcrescentic, and stands on the second superior labial. A trapezoid 

 dorsal bounds the large superior preocular in front. Four rows of scales separate 

 the orbit from the labials. The scales of the top of the head are flat, hexagonal, 

 and faintly keeled; twelve series separate the superciliaries, which are quite 

 narrow. Inferior labials thirteen, the first large, and with the second in contact 

 with the geneials. The latter form but one pair, are squarely truncate in front, 

 and narrowly rounded behind. Gastrosteges 200; urosteges, double 32, quad- 

 ruple 17; caudal spine well developed. Color (in spirits) fawn brown, with 

 twenty-three reddish-brown median rhombs on the dorsal region. The lateral 

 angles of these are dark spots, sometimes isolated, and do not extend below the 

 fifth row of scales. On the middle of the body the rhombs have pale centres, 

 posteriorly they are darker, and become confluent into a zigzag band. Tail 

 dark brown, with narrow, light cross bands. Lower surfaces all greenish-yellow, 

 except the throat and chin, which are white (in spirits). A black band extends 

 from the eye above the labials, and is broken upon the neck into a series of black 



spots. Top of head uniform brown. 



M. 



Total length ^^^ 



Length of tail • -^^^ 



091 

 " of gape ....•••••• '"^^ 



One specimen from Sipurio. 



This species is of much interest as increasing our knowledge of the structural 

 and geographical range of the genus Lachesis, heretofore represented only by the 

 L. mutus of Surinam. As such, it has the distal caudal scutella four-rowed and 

 tubercular. 



OEOTALI. 



124. Crotalus DtTRissus, Linn. ; C. horridus, Auctor., Pliiv.; Caudisona durissa, Laurenti. 



This large species was not found by Dr. Gabb in Talamanca, but was brought 

 by Dr. Van Patten from the neighborhood of San Jose. 



