ON THE BATRACHIA AND REPTILIA OF COSTA RICA. 143 



102. Tantilla arjiillata, Cope, sp. uov.; Tantilla melanocephala^ var. Cope, Proceed. Acad. 

 Philada. 1871, p. 205. 



Form slender ; scales in fifteen longitudinal rows. Rostral plate not protube- 

 rant ; prefontals three times as long as internasals, equalling the parietal suture 

 of the frontal. Frontal wide, considerably shorter than parietals. Nasals little 

 notched below, the posterior reaching the preocular. Seventh superior labial much 

 the largest; temporals 1-1, the anterior bordering the postoculars. Inferior labials 

 six, first pair slightly united, four in contact with geneials, fourth largest, elongate, 

 touching both geneials. Gastrosteges 166 ; anal divided ; urosteges 50. 



Above chocolate-brown ; head and nape for five scales, black, with a yellow spot 

 in the individual described, on the end of the muzzle, on the posterior part of each 

 parietal plate ; and two on the lip behind the eye, and one below the nostril. The 

 black is bordered behind by a yellow collar of two scales width, which is also bor- 

 dered by black behind except where it sends ofi' on the third and fourth rows of 

 scales on each side a narrow light band Avhich extends to the tail. Below this, 

 and on the median row of scales, is a narrow brown line. Below immaculate. 



Middle Costa Kica ; Dr. Van Patten. 



The species of Tantilla may be distinguished as follows :^ 



I. Superior labials six; orbitals 1-1. 



Muzzle produced ; preorbital not in contact with superciliary nor nasal ; three 

 longitudinal bands. T. calamarina. Cope. 



Muzzle less produced; preorbital in contact with superciliary and nasal; temporal 

 one; three bands. T. bimaculata, Cope.* 



Temporals two ; no bands. T. gracilis, B. Sc G. 



II. Superior labials seven ; orbitals 1—1. 



Coloration uniform. T. planiceps, Blainv. 



III. Superior labials seven ; two postoculars. 



a. Postnasals in contact with preocular, or nearly so. 



* Tantilla bimaculata, Cope, sp. nov. 



Scales in fifteen rows. Rostral strongly protuberant beyond mouth. Nasals little notched 

 below by first labial ; postnasal barely or quite reaching preocular. Frontal large, longer than 

 suture to rostral, not presenting an angle forwards ; superciliaries not reduced ; parietals about 

 as long as the frontal. One temporal barely touching postocular ; fifth upper labial highest. 

 Five inferior labials, first pair widely separated, only three in contact with geneials, third largest 

 in contact with both geneials. Gastrosteges 130; anal double; urosteges 34. 



Color light brown with three darker narrow longitudinal bands. Top of head dark colored 

 in continuation of the middle band ; on each side of the occipital plate behind a large yellow 

 spot. Below immaculate. 



This well-marked species was found near Mazatlan by Mr. Bischofi", and is No. 6834 of the 

 Smithsonian Catalogue. 



