1909. ] POSTCAVAL VEIN IN MAMMALS. 507 
along the ureter. Their course is thus somewhat oblique. In 
this we have an exact resemblance to ). novemcinctus. On the 
left side the renal vein is quite single (it is double in both of the 
species already mentioned) and it gives off just before entering 
the kidney two veins like those of the opposite side of the body. 
The left suprarenal vein enters the postcaval, just anteriorly to 
the influx of the left renal. The point at which the postcaval 
bifureates is behind the renal veins and seems to me to be pretty 
well intermediate in position as compared with the two forms 
studied by Hochstetter. The rete formed by the candal vein is 
large, as in Dasypus setosus. It is a complex rete mixed up with 
the caudal artery in a way which I have not disentangled. 
I have also had the opportunity of examining a fourth species 
of Dasypus, viz. D. villosus. Of this species I have dissected two 
examples, but am only able to say something concerning the 
details of the postcaval vein in one. Of the other I can only say 
that it showed the typical condition of this genus. It is of course 
important even to say this. For in some mammals which show 
a double postrenal postcaval (e. g. Jctonyx*) there is variation, 
some examples being normally Hutherian without a postrenal 
doubling. In one example of D. villosuws the veins in question 
were simpler than in the other types hitherto dealt with. The 
renals were asymmetrical as in the others; but there was only a 
single renal vein on each side. These two veins appeared to me 
to be of about the same size. The left suprarenal vein entered 
the left renal only just before its connection with the postcaval. 
From each renal arose a single ovarian vein descending parallel 
to the longitudinal axis of the body as in the other species. On 
both sides the lumbar veins were two, opening each into the 
divided region of the postcaval. I did not note these veins in the 
other species. 
I am also able to add to what is known concerning the post- 
caval vein and its branches in the Armadillos some notes upon 
these veins in Lysiwrus unicinetus, a species of which I have 
dissected one example which was a male. In this Armadillo the 
division of the postcaval is more marked than in any species of 
Dasypus (among those referred to in the present communication). 
The division just extends anteriorly to the influx of the renal 
veins; and the conditions which obtain in this genus are there- 
fore like those which occur in Mephitis tf occasionally, where, 
however, it is only one renal (the left) that opens into the divided 
portion of the postcaval. In the Armadillo with which I am now 
concerned both renal veins are thus separate from each other. 
Another noteworthy point about this species is the greater calibre 
of the renal vessels on the left side of the body as compared with 
those of the right. They were vast in the specimen which I 
dissected and turgid with blood. On the left side of the body 
* Of, Beddard on Glalidia &e., P. Z. S. 1909, p. 491. 
+ P, Z. 8. 1909, p. 492. 
Baie 
