170 Dr. A. Giinther on Leptodeira torquata. 



separated the former, referring it to a genus which he calls 

 Heterurus, because the subcaudal plates are said to be partly 

 simple and partly bifid. This, however, must be merely acci- 

 dental in some individual, and an exception, all the specimens 

 which I have examined (and their number is nearly fifty) show- 

 ing invariably all the subcaudals bifid. A character which I 

 should have been glad to admit into the generic diagnosis of 

 Leptodeira was the presence of a posterior grooved tooth ; but this 

 character must now fall to the ground, according to my view, — 

 the species which I am about to describe exhibiting the poste- 

 rior tooth smooth, although strong. It is so similar to Lepto'- 

 deira annulata that, at the first glance, one might be tempted to 

 pronounce it merely a variety in which the neck, usually of a 

 light brown colour in L. annulata, has become white. The 

 specific difference, however, may be easily proved by a closer 

 examination, when they will appear in the same relation to each 

 other as Coronella Icevis and Coronella cucullata. According 

 to Dumeril's system, the new species would enter the genus 

 Liophis. 



Leptodeira torquata. (Plate X. A.) 



Diagnosis. Anal bifid. Scales in twenty-one rows. Posterior 

 maxillary tooth longest and strongest, and separated from the 

 others by an interspace. Brownish grey, with a vertebral series 

 of brown spots, some of which are confluent into a zigzag band ; 

 neck with a white collar. 



Habitat. Nicaragua; Island of Laguna. The two typical 

 specimens are in the Derby Museum at Liverpool. 



Description. The head is rather broad and depressed, the 

 snout rounded ; the eye is of moderate size, its vertical diameter 

 being about one- third the width between the eyes; the trunk is 

 rounded, the tail of moderate length, or rather short. The ros- 

 tral reaches to the upper surface of the snout; the anterior 

 frontals are nearly square, and much smaller than the posterior 

 ones, which, broader than long, are bent downwards to the side 

 of the snout ; the vertical is pentagonal, longer than broad, and 

 of somewhat different form in the two specimens ; the occipitals 

 are rounded posteriorly. Nostril situated between two nasals ; 

 loreal square ; two anterior oculars, the lower of which is small, 

 and intercalated between the third and fourth labial shields; 

 two. posterior oculars ; eight upper labials, the fourth and fifth 

 of which enter the orbit. There is one elongate temporal shield 

 in contact with both the oculars ; the other temporals, five in 

 number, are scale-like. The medial lower labial is triangular, and 

 rather small ; nine lower labials, the first of which is in contact 

 with its fellow behind the median shield. There are two pairs 



