378 Analytical Notices of Books. 
A third Herpetological Memoir derived from the investigation of the 
treasures contained in the magnificent collection of the Leyden Museum, 
is entitled, ‘‘ Untersuchung der Speicheldriisen bei den Schlangen.’’ Its 
chief purpose is to make known an important fact in the economy of 
certain snakes, in regard to which much uncertainty existed, their bite 
having sometimes been found fatal, while at others itis perfectly harmless. 
This anomaly is clearly accounted for by an observation first made by 
Prof, Reinwardt on the Dipsas dendrophila of Java, afterwards extended 
by Dr. Boie to other species of Dipsas and Homalopsis, and still further 
confirmed in several other genera by M. Schlegel, the authour of the 
present paper. All these snakes have teeth nearly similar in character to 
those of the genus Coluber, excepting that the last on either side of the 
upper jaw is longer than the rest, and has adeep sulcus on its anterior 
surface, the base of which corresponds, as in the true poisonous fangs, 
with the termination of the excretory duct of a poison-secreting gland. 
As the sulcate poison-teeth stand much farther back within the’ mouth 
than the fangs of Vipers, Rattle-snakes, &c. it is obvious that the danger 
resulting from the bite of the snakes that possess them is contingent on 
the extent to which the mouth is opened in the act of biting, or in other 
words on the participation or non-participation of the hinder teeth in the 
infliction of the wound. There exists a direct transition from the snakes 
in question to the true poisonous snakes by the intervention of Flaps, 
Naja, Bungarus and Trimeresurus, in which the anterior portion of the 
upper jaw is gradually shortened, the imperforate anterior teeth become 
fewer in number, and the elongated posterior tooth is perforated as in the 
Vipers, but has in addition an anterior fissure communicating with the 
whole length of the cavity. These modifications are well represented in 
a plate accompanying this important memoir. 
The only Ichthyological paper in the present volume is the commence- 
ment of a ‘ Vergleichende Betrachtung des starren Geriistes welches das 
‘* Fortpflanzungsgerathe tragt und umgiebt,”’ by Dr. Ritgen. In this first 
section of his proposed comparative osteology of the pelvis and its 
auxiliary bones and cartilages, the authour confines himself, with the 
exception of a few general observations, to the description of these 
organs as they exist in Fishes, the lowest animals in which they can be 
clearly demonstrated, unless we consider as the commencement of a pelvis 
