318 PROCEEDINGS OF THE ACADEMY OF 



Body exceedingly slender and compressed. Gastrosteges 250, anal divided, 

 urosteges 157. Total length 2 feet 9 inches, tail 105 inches; length of head 

 5 lines. 



Ashy white, with fifty transverse black light-edged spots on the body, 

 which approach closely on the median line ; on the tail 39 spots. Below, 

 belly minutely punetulated ; tail brown spotted. 



The absence of the dorsal shields would indicate a wide separation of this 

 species from the type of the genus H. cenchoa L., but for the existence 

 of H. gemmistratus Cope, in which this series is much narrowed, 

 approaching the ordinary form of scale. 



Smithson., No 6563; Schott, No. 903. This, with the three species follow- 

 ing, form part of the collection made by Dr. Schott under direction of Governor 

 Ilarregin, of Yucatan. 



Mesopeltis sanniolus m. genus et spec. nov. 



Char. Gen. Maxillary, palatine and pterygoid bones elevated laminifcrm, 

 the first bearing slender teeth to opposite middle of orbit. Cephalic shields 

 normal; posteiior genials quite small, the first pair united into an ovoid 

 shield which is in contact with the symphyseal. No scale pores. Anal divided. 

 Body compressed, head quite distinct, with large eye and vertical pupil. 

 Scales smooth, without larger vertebral series. 



Char. Specif. Muzzle contracted, labial margin and mandible especially so, 

 from under the orbit. Rostral not visible from above ; two short nasals ; 

 loreal narrow, erect ; preoculars two, very narrow, the inferior very small. 

 Vertical, nearly twice as long as broad at its middle ; a little longer than 

 parietal suture ; its outlines straight. Superior labials eight nine, the sub- 

 orbitals the fourth and fifth, longitudinal. Inferior labials ten, the anterior 

 four very small, the fifth narrow, oblique. Back and belly equally rounded ; 

 scales in fifteen series. Tail cylindrical. Gastrosteges 156 ; urosteges 55 

 .(approximately). 



Length of head and body 11 inches. 



Above light brown, with one series of small dark brown spots on the median 

 line separated by intervals nearly equal to their diameter. A broad nuchal 

 band continued to middle of frontal shield. Lips and sides with numerous 

 pale brown spots ; under surfaces generally with minute brown punctu- 

 lations. 



Smithsonian No. 6564. 



This is another of the Lrptognath forms which occur in the tropics of both 

 worlds, but most abundantly in the neotropical region. It is more distinct 

 from Leptognathus D. B. than is Tropidodipsas Gthr. 



Conophis concolor m. sp. nov. 



The largest species of the genus : form stout, tail A\ times in total length. 

 Scales in nineteen rows, broad. Frontal region and muzzle narrow elongate, 

 anterior to frontal shield, equal length of latter, and considerably longer than 

 occipitals. Rostral with a strong concentric groove below, nasals distinct, 

 elongate ; loreal longer than high, parallelogrammic ; preorbitals not reaching 

 frontals ; postorbitals two, rather large. Superior labials eight, eye over 

 fourth and fifth, penultimate higher than long, last nearly as elevated. One 

 elongate inferior temporal, the superior subdivided, (in two specimens.) 

 Inferior labials 10. Gastrosteges 166', urosteges 72. Color above pale yel- 

 lowish brown ; a brown band, from the end of the muzzle through the eye, is 

 lost a short distance behind opposite the mouth, and on one of the specimens 

 two incomplete dotted lines extend from the sides of the frontal, and, diverg- 

 ing, are lost on the nape. Superior labials and rostral margined with brown 

 below. Under surfaces light yellow. 



Total length 32 inches. 



Two specimens (138). 



[Nov. 



