1885] i "* 5 -*- [Cope. 



scales. The centres of the spaces between them on the sides are occupied 

 by a light brown spot. Each gastrostege has a dark brown spot on its 

 extremity, and the rest of the scutum is thickly dusted with brown. 

 Thirty-nine cross-bands on upper surface of tail. Three brown chevrons 

 on the parietal region, directed backwards, the anterior commencing with 

 the superciliary. Muzzle and sides of head brown speckled ; throat and 

 chin immaculate. 



4. Dipsas cenchoa L. Nos. 14119-20. 



5. Drymobius boddaertii Seetzen. No. 14117. 



6. Elaps nigrocinctus * Girard. No. 14115. 



7. Bothrops atrox L. No. 14114. 



III. Chiriqjji. 



Htla microcephala, sp. nov. 



Fingers free ; toes webbed nearly to the palettes of the third and fifth 

 digits. Vomerine teeth in two fascicles between the nares, with their 

 anterior edge in line with the anterior edge of the latter. Membranum 

 tympani round, its diameter one-third that of the eye. The latter equals 

 the length of the muzzle, which is short and rather deep, and not promi- 

 nent. The external nostril is at one-fourth the length posterior to the 

 apex. The head is small in its dimensions, its length to the line of the 

 posterior border of the tympana entering the length of the head and body, 

 three and a half times. The eyes are little prominent. The general form 

 is slender, and the hinder legs are long, the heel reaching to beyond the 

 end of the muzzle. The metatarsal tubercles are not distinguishable as 

 dermal differentiations. Digital dilatations not so large as the tympanic 

 membrane. Skin everywhere smooth on superior surfaces. Length of 

 head and body, .0275 ; do. of anterior limb from axilla, .014 ; of posterior 



* A species of this genus has been obtained by Francis Sumichrast, on the 

 Pacific side of the Isthmus of Tehuantepec, which I believe to be undescribed. 

 It is referred to in the Proceedings of the American Philosophical Society, 1869, 

 p. 102, as Elops aglceope ; but it is distinct from this species. I propose that it 

 be called Elaps ephippifer. It has the seven superior labials and fifteen rows of 

 scales of the most of 1 lie American Elaps, and the labials are separated from 

 parietals by one row of temporals. The rostral plate is transverse and not par- 

 ticularly prominent, and its posterior border is very openly angulate. The 

 frontal plate has long parallel lateral borders, and much shorter posterior ones. 

 Gastrosteges, 218; anal divided; urosteges, 43. There are seventeen black rings 

 on the body, which encircle the abdomen, covering a length of four and a half 

 scales and five or six gastrosteges. They are separated by nine or ten scales, 

 and have a wide yellow border of one and a half or two scales in width. The 

 entire space between these yellow borders is occupied by a large black spot, 

 which descends on each side to the second row of scales. The remaining space 

 between the yellow borders is red. There is a wide black entire collar, which 

 cuts off the apex of the parietal shields. The muzzle and front are black as 

 far as the anterior part of the parietals. 



The wide yellow borders in this species are like those of the E. euryxanUuis, 

 while the black saddles represent the black spots of the E. agloeope. 



PROC. AMER. PHTLOS. SOC. XXIII. 122. 2j. PRINTED FEBRUARY 11, 1886. 



