128 ON THE BATRACHIA AND REPTILIA OF COSTA RICA. 



OPHIDIA. 



SCOLECOPHIDIA. 



65. Helminthophis frontalis, Peters, Monatsb. K. Preuss. Ak. 1861, p. 511. 



Unknown to me. 



Although no Stenostomidce have yet been brought from Costa Kica, to my 

 knowledge, yet they doubtless exist there, as the Stenostoma alhifrons has been 

 sent to the Smithsonian Institution from Panama by C. B. Adams, and a second 

 species of the genus has been obtained in the western part of Tehuantepec by Dr. 

 Francis Sumichrast. This appears to me to be new to science, and may be 

 described as follows: I first compare it with those species of the genus which have 

 but two labial plates, and no production nor angulation of the rostral plate, and in 

 which the superciliaries are in contact with the first scale of the middle series, 

 which is of the same form as those of the body. This species belongs also to 

 those with large transverse temporal scales, and a narrow superciliary. 



a. Superciliary in contact with first labial. 

 Last labial reaching one of the two temporals. S. albifrons. 



aa. Superciliary superior not reaching first labial. 



/3. Last labial in contact with but one temporal. 

 v. Two temporals. 

 Rostral wide, nostril inferior; caudal scales 18; black. S. groutii. 



Rostral narrow; first labial not rising to eye; caudal scales 15; black lined. 



S. phenops* 



Rostral narrow; nostril terminal; first labial reaching eye; caudal scales 26; 

 black lined. S- melanoterma. 



lyy. One temporal. 

 Rostral narrow; first labial not rising to eye; caudal scales 15; black lined. 



S. signatum. 



* The Stenostoma phenops from Tehuantepec is represented by numerous specimens, which 

 are of small size and dark colors. Scales in 13 rows. The eye is distinct, and the nareal suture 

 extends to the rostral plate. The lower surfaces are without marking, but the scales of the upper 

 surface are black with pale borders. There are three white spots ; one on the end of the rostral 

 plate ; one at the apex, and one on the under side of the tail. Total length, m. .156 ; tail, .009. 

 The same species was obtained from near Coban, Guatemala, by Henry Hague. 



The Stenostoma melanoterma, Cope, of the above table, was brought from Paraguay ; see 

 Proceed. Acad. Philada. 1862, p. 350. The 8. groutii, Cope, is a new species, discovered by Dr. 

 Alden S. Grout, near the Umvoti Mission, Zulu Country, South Africa. Scales in fourteen rows. 

 The nasal plate is much narrowed at the labial border, and the first labial only rises as high as 

 the nostril, which is half way from the edge of the lip to the orbit. Color uniform black, except 

 a white spot at vent and one at apex of tail. Dedicated to Dr. Grout, who has sent numerous 

 valuable specimens from the Zulu Country to Philadelphia. 



