494 MR. F. E, BEDDARD ON THE STRUCTURE | Apr. 27, 
absolute line of distinction can, it is true, be drawn between the 
Arctoidea and the Ailuroidea in the arrangement of these veins. 
But whereas among the Afluroidea only a few forms (e. g., 
Suricata, Herpestes smithi) can be mentioned in which the veins 
are approximately symmetrical, there are more Arctoidea in which 
this symmetry occurs, viz. in the species Mephitis mephitica, [ctonyx 
capensis, Ursus syriacus. Moreover, in Ursus an absolutely 
‘‘Marsupial ” disposition of the spermatic veins is to be met with, 
where both are connected with the renal veins. Finally, the 
lumbar veins are more usually restricted to a single vein upon 
each side of the body in the Arctoidea; while they are prevalently 
double in the Ailuroidea. That this feature is more archaic than 
that which characterises the Alluroidea can hardly be said. I 
merely dwell upon the fact that there is a tendency to the 
establishing of this difference between the two groups. But in 
dwelling upon these facts it must not be forgotten that some 
Arctoidea are apparently exactly like some Ailuroids in the dis- 
position of these veins. 
Doubtless it cannot be said that the comparisons and contrasts 
amount to a great deal. But they have at least an interest in 
connection with the variations in the arrangement of the postcaval 
and its branches in the Common Cat, “ Felis domestica.” The 
veins of this animal have been lately studied in so large a number 
of specimens as 605*. This large number probably gives some 
real idea of the range of variations in these veins. In no less 
than 23 examples the author found in the posterior region a 
double postcaval, such as I have described in Jetonyx and 
Mephitis. In 7 there was a left postcaval, instead of the normal 
Kutherian right, In others, again, the spermatic veins, instead 
of their normal asymmetry which is certainly the prevalent dis- 
position in the Carnivora, as I have pointed out, both entered 
the postcaval directly. 
$ Other Blood-vessels. 
The cerebral arteries of Galidia elegans are like those of other 
Carnivora, differing only from those of certain forms in details. 
There is at the posterior end of the medulla a strongly marked 
rhomboid of arteries, as in many other Carnivora. This is asso- 
ciated with a large anterior spinal artery and vertebral arteries. 
The latter are single where they join the lateral angles of this 
rhomboid, and not double as they are in Helictis personata *. 
The middle cerebellar arteries are two on one side and one on the 
other (left); but the latter divides into two very shortly after its 
emergence from the basilar artery. It is to be noted that these 
* W. Darrach, “ Variations in the Postcava and its Tributaries, as observed in 
605 Examples of the Domestic Cat,’ Amer. Journ. Anat. vol. vi. 1907, Anat. Rec. 
p. 30. 
+ Beddard, “On the Anatomy of Helictis personata,” P. Z.S. 1905, p. 22, 
text-fig. 8. 
