92 Mr. G-. A. Boulenger on a new Snake. 
The African species of Glaucoma which, in my opinion, 
are entitled to recognition are thirteen in number, and may be 
distinguished as follows : — 
A. Ocular bordering the lip, separated from the 
lower part of the nasal by a single labial. 
a. Snout hooked, the prseoral portion flat or 
concave interiorly. 
Diameter of body more than 100 times in the 
total length G. macrorhynchus , Jan. 
Diameter of body less than 100 times in the 
total length G. rostrata , Bocage. 
b. Snout rounded. 
a'. Supraocular nearly twice as broad as 
long, followed by a single transversely 
enlarged shield G. Emini , Blgr. 
b'. Supraocular small. 
a". Rostral not extending to the level of 
the posterior border of the eyes. 
a. Diameter of body 40 to 57 times in 
the total length. 
First labial as large as lower part of nasal .... G. narirostris , Ptrs. 
First labial smaller than lower part of nasal ; 
length of tail 25 to 30 times in total G . brevicauda , Bocage. 
First labial smaller than lower part of nasal ; 
length of tail 8 to 13 times in total G. nigricans , Schleg. 
(3. Diameter of body 65 to 90 times in 
the total length. 
Nasal semidivided; length of tail 14 or 15 times 
in total G. Cairi , D. & B. 
Nasal completely divided ; length of tail 9 times 
in total G. longicauda , Ptrs. 
b Rostral extending to the level of the 
posterior border of the eyes. 
Rostral not twice the width of the nasal G. conjuncta , Jan. 
Rostral at least twice the width of the nasal . . G. scutifrons, Ptrs. 
B. Ocular bordering the lip, separated from the 
lower part of the rostral by two labials. 
Supraocular large, as broad as the shield 
following G. Sundevallii , Jan. 
Supraocular small G. bicolor , Jan. 
C. Ocular not reaching the lip G. dissimilis , Bocage. 
In addition to the above-described Glaucoma , the following 
