352 Dr. A. Giinther on neiv Species of Snakes 



Homalocranium moestum. 



Entirely deep black, with a broad yellow collar extending over 

 the hind part of the occipitals ; laterally ; to the eyes ; and below, 

 over the ivhole chin and throat. 



Anterior frontals very broad, with the lateral portion produced 

 backwards, about half as large as the posterior frontals. Vertical 

 six-sided, much longer than broad, with an obtuse angle in front, 

 and an acute one behind ; occipitals rounded behind, as long as 

 the vertical and posterior frontals together; posterior nasal low, 

 elongate, in contact with the single prseocular ; two postoculars ; 

 upper labials seven, the third and fourth entering the orbit, the 

 last being the largest and highest. The median lower labial is 

 in contact with the chin-shields, which are twice as long as broad; 

 there follow two or three other pairs of small scale-like chin- 

 shields. Scales smooth, in 15 rows. Ventrals 150, anal bifid, 

 subcaudals 32-|-. . • (tail injured). 



The posterior maxillary tooth is stout, and provided with a 

 very shallow gi'oove. 



A single specimen has been found by Messrs. Salvin and 

 Godman in the Province of Peten : its head and trunk are 

 10 inches long; probable length of the tail 2f inches. 



Mizodon longicauda. PI. V. fig. A. 



Scales in seventeen rows ; anal bifid. Length of the tail more 

 than one-third of the total. A reddish-yelloiv, black-edged collar. 



Habit like that of Dromicus mela7iotus, but with a longer tail. 

 Snout rather short ; rostral shield not extending on the upper 

 surface of the crown ; frontals small ; loreal square ; one prae- 

 ocular, just reaching to the upper surface of the head ; three 

 postoculars ; eight upper labials, the fourth and fifth entering 

 the orbit. Temporals 1 -1- 2 : the anterior is elongate, in contact 

 with the two lower postoculars ; the upper of the two posterior 

 temporals also is elongate, bordering the occipital. Two pairs 

 of chin-shields, the posterior of which are much longer than the 

 anterior; the anterior in contact with four labials. Ventrals 137, 

 without any keels; subcaudals about 100*. Maxillary teeth 

 gradually increasing in length behind, in one continuous series. 

 Upper parts uniform brownish olive. A reddish-yellow band 

 across the nape, broadly edged with black in front and behind ; 

 the hinder black edge is the more intense, and is again followed 

 by an indistinct lighter band. Upper lip yellow, with some 

 black spots; lower parts nearly uniform yellowish. 



Fernando Po. Length of the cleft of the mouth ^ inch, of 

 the trunk IH inches; probable length of the tail 8 inches, of 

 which 5 1 inches are preserved. 



* The tail is mutilated : 64 subcaudals on the preserved part. 



