22 MR. F, E. BEDDARD ON THE [May 2, 
to the arteries of the brain, which are most satisfactorily injected 
in my specimen and which show all the Arctoid characters*. 
The rhomboidal area formed by the bifurcation of the anterior 
spinal and its junction with the basilar is of considerable calibre 
and uniform throughout, as in all Carnivora which have been 
examined. 
The vertebral arteries are, however, peculiar in their mode of 
joining this rhomboidal vessel. Each vertebral artery in fact 
divides before joining the rhomboidal, and each branch opens 
separately into it, as is shown in the accompanying figure (text- 
fig. 8). The carotids join the circle of Willis just before the 
middle cerebral arteries are given off. 
Text-fig. 7. Text-fig. 8. 
Text-fig. 7—Brain of Helictis personata, dorsal aspect. 
Cr. Crucial fissure; Za¢. Lateral fissure; Orb. Orbital fissure; Pe.§S. Precrucial 
fissure; S.S. Supra-Sylvian fissure. 
Text-fig. 8—Brain of Helictis personata, ventral aspect, with the arterial system 
shown in thicker and thinner black lines. The dotted lines delimit regions of 
the brain. 
b.a. Basilar artery ; Ca. Carotids; Call. Callosal arteries ; P.c. Posterior 
cerebellar; v.a. Vertebral arteries. 
Anteriorly the circle of Willis is completed by the fusion of the 
two callosal arteries, that of the right side being distinctly smaller 
than that of the left. 
* Beddard, P, Z.S. 1904, vol. i. p. 183. 
