1909. ] OF THE CARNIVORE GALIDIA ELEGANS. 
arteries arise behind the sixth nerves. The anterior cerebellar 
arteries arise very shortly after the bifurcation of the basilar. 
Excepting for the fact that the cerebellar arteries are strictly 
paired, I found the arteries of the Common Otter precisely as has 
been just described for Galidia. 
Dr. Tandler* has figured the cerebral arterial system of the 
Seal, and has represented the anterior spinal as of large size, as 1s 
the case with many Carnivora including those to which I have 
referred in the present communication. In a specimen of the 
Common Seal which I dissected some time since this was not the 
case. ‘The anterior spinal was very slender, and communicated 
with the two very stout vertebrals by two very slender branches. 
The middle cerebral arter My is single, and lies, as I have mentioned 
in Galidia, behind the origin of the sixth nerve tT. The cirele of 
Willis is joined anterior ly. by the anterior commennioatind artery. 
I am unfortunately not quite certain about this part of the 
cerebral arterial system in G'alidia; but I believe it to be like 
that of Helictis figured by myself ¢. 
The system of cerebral arteries in an example of Cryptoprocta 
Jerox may be compared with that of the types already described 
by others $ as well as by myself. The first remarkable fact is the 
asymmetry of the arteries at the end of the medulla, which, how- 
ever’, is very possibly an individual peculiarity, as the asymmetry 
in the cerebral arteries of yraa descrihed by myself || proved to be 
later §. Both the anterior spinal and the vertebral arteries are 
stout. Although the main paired middle cerebellar artery lies 
behind the sixth nerve, there is a slender branch on the right side 
which lies in front of it. The anterior cerebellar artery hes just 
behind the bifureation of the basilar. The arrangement of the 
anterior communicating artery and of the anterior cerebrals 
generally is very much as I have figured in Viverra civetta**. 
I do not think that the cerebral arterial system of Zyana crocuta 
has been deseribed. The specimen which I have had the oppor- 
tunity of examining showed some differences from other Carnivora. 
Beginning as before with the posterior end of this arterial system, 
it is to be noted that the vertebral arteries are large—which is a 
general character of the group. On the other hema, there is no 
definite rhomboid-shaped arterial area at this point—z. ¢., at the 
posterior end of the medulla—which is so characteristic of Carni- 
vores. There are, in fact, two anterior spinal arteries, smaller than 
the vertebral, which run back at least for some little way without 
joining. I have no evidence, in fact, that they do ever join; for 
* “ Zur vergl. Anatomie der Kopfarterien bei den Mammalia,” Denkschr. k. Akad. 
Wiss. Wien, Bd. Ixvii. 1899. 
+ I have already (P.Z.S. 1904, vol. i. p. 191) directed attention to the varying 
position of these Bunnies with reference to the sixth nerve. 
3 12 Z. S. 1905, p p.- 22, text- fig. 8 
§ See also Bertha de Vriese, “Sur la Signification morphologique des Artéres 
cérébrales,” Arch. d. Biol. xxi. 1904, p. 357. 
|| P.Z.S. 1904, vol. i. p. 187, text-fig. 18. { P. Z.S. 1909, p. 166. 
a* PZ... 1904, vol. 1. p. 194, text-fig. 21 B. 
