404 



inches, lines. 



Distance between the extremity of the snout and 



the tympanum , 0 10 



Distance between the tympanum and the vent 2 7 



Length of the tail 7 6 



Distance between the extremity of the snout and 



the anterior margin of the orbit 0 5 



Distance between the anterior angles of the orbits 0 3J 



Length of the anterior extremity 1 3 



of the third finger 0 5 



of the posterior extremity , 2 7 



of the foot . , 1 4 



of the fourth toe 0 11 



3. CUSTA BICARINATA, L. 



The exact habitat of this species was not known before. 



4. Monoplocus, n. g. (Teidce.) 



Tongue elongate, free, not sheathed, terminating in two very fine 

 points. Palatine teeth none ; the posterior teeth in the jaws bi- or 

 tricuspid. Tympanum distinct. Throat with a single fold. Scales 

 of the back exceedingly small, those of the sides granular ; gular and 

 ventral shields keeled. Tail rounded, covered with keeled and verti- 

 cillated scales of moderate size. Femoral pores none. 



Monoplocus dorsalis, n. sp. 



Diagnosis. — A greenish-white longitudinal streak from the extre- 

 mity of the snout to the middle of the back, where it is gradually lost. 



Description. — The general habit is slender. The snout is of mode- 

 rate length, pyramidal ; the nostril is laterally situated between the 

 two nasals. 'The successive series of shields covering the upper 

 surface of the head is as follows : — 1. The rostral shield is obtusely 

 conical, as high as wide, with the posterior angle acute and produced 

 backwards on the upper surface of the head. 2. A pair of anterior 

 nasals, quadrangular, touching each other behind the rostral, and 

 enclosing the greater part of the nostril. 3. A single anterior 

 frontal, hexagonal, with the anterior and posterior angles obtuse, 

 and with the outer sides shortest and in contact with the posterior 

 nasal and the loreal. 4. A pair of posterior frontals, irregularly 

 pentangular. 5. A single anterior parietal, the largest of the shields 

 of the head, pentagonal, with the anterior side rather curved, and 

 with the two hinder ones shortest. 6. A pair of posterior parietals, 

 irregularly quadrangular. 7 . Five occipital shields, one forming the 

 centre, the others being symmetrically arranged. 8. The upper 

 eyelid is covered by two larger and two or three smaller shields. 



The lateral shields of the head are the posterior nasal, the loreal, 

 which is larger than the former, and three oculars, forming the an- 

 terior and lower margin of the orbit. There are six very narrow 

 upper labial shields and several smaller ones behind. 



