20 MR. G. KREFFT ON A NEW AUSTRALIAN SNAKE. [Jan. 26, 
loped, for instance, than in a Rodent of corresponding dimensions. 
Another important point to notice is, that the ventricles of the optic 
lobes, the persistence of which is so characteristic of the oviparous 
Vertebrates, are obliterated in the Echidna. 
As is well known, there is considerable variation in the form and 
relative size of the four eminences on the surface of the optic lobes, 
and of the distinctness with which they are marked off from one 
another, in different mammals. In the Sloth, and more especially 
the Wombat, they are scarcely, if at all, more sharply defined than 
in the Lchidna, which therefore, in this respect, presents no trenchant 
deviation from the ordinary Mammalian type. 
EXPLANATION OF THE WOODCUT. 
Middle portion of the brain of the Echidna (E. hystrix), twice the natural size. 
Fig. 1. Seen from above. The cerebellum turned back to show its superior pe- 
duncles. 
Fig. 2. Side view. 
a. Optic thalamus. 
b. Peduncle of the pineal body. 
c. Pineal body. 
d. Anterior eminence of the optic lobe (natis). 
e. Posterior eminence of the optic lobe (¢estis). 
J. Superior peduncle of the cerebellum (processus a cerebello ad testes). 
g. Cerebe}lum. 
h. Optic track. 
i. Fifth nerve. 
2. DESCRIPTION OF ASPIDIOTES MELANOCEPHALUS, A NEW 
SNAKE FROM Port Denison, N.E. Ausrratia. By Gerarp 
Krerrt, ActiInG CurATOR AND SECRETARY, AUSTRALIAN 
Museum, SYDNEY. 
Fam. Borpz. 
ASPIDIOTES, nov. gen. 
Crown covered with broad shields reaching behind the eyes; the 
remaining part of the head scaly; labial shields without pits, the 
front ones high and narrow, the hinder shields lower aud broad. 
Nostrils lateral, in the middle of a plate, two loreals, two anterior 
and four posterior oculars ; superciliaries broad, rather prominent 
above the eye; nasal shield very large, much produced backwards, 
and deeply grooved on its lower edge. Scales smooth, in fifty-two 
series on the middle of the body ; ventral plates rather narrow ; sub- 
caudals entire, except the last ten or twelve, which are divided. 
Tail conical, prehensile, ending ina blunt point. Head rather high, 
of moderate size; teeth not very large (smaller than in Morelia). 
Body thick and compressed. 
ASPIDIOTES MELANOCEPHALUS. 
Seales in 52 series on the middle of the body. Ventral shields 
narrow, 330. Anal entire. Subcaudals 515. 
