1889.] ON THE LEFT CARDINAL VEIN IN THE FROG. 145 
3. 2 
millim. millim 
Wotal lenpehyt . sss ee 228 200 
RGA? EEGIe ss Nose, eR 2S 28 
Wadthiof Héadth.. S24. 20%. . 4 20 20 
BQO wos gx ecw inches geht Oe SAU FZ 
Horelimibunee we vee 2 Stay 39 
GinG@elimbe seeaeiecrests tis LOC 57 
stat lees rere HORE: NORRIE 114 100 
From the Sierra de Uspallata and the desert west of Catamarca. 
Differs from U. torquatus, to which it is closely allied, in the 
longer head, shorter digits, and shorter tail. 
EXPLANATION OF PLATE XY. 
Fig. 1. Gymnodactylus horridus, with enlarged view of chin. 
2. Urostrophus scapulatus 9 , with upper view of head. 
8. On the occasional Persistence of the Left Posterior 
Cardinal Vein in the Frog, with Remarks on the 
Homologies of the Veins in the Dipnoi. By W. Newron 
Parker, Ph.D., F.Z.S., Professor of Biology in the 
University College of South Wales and Monmouthshire. 
[Received March 8, 1889.] 
According to the recent researches of Hochstetter ', the postcaval 
vein arises in part independently (“ Leberabschnitt ’’), and in part 
from that portion of one (Amniota) or of both (Amphibia) posterior 
cardinal veins which receive the venz renales revehentes (‘* Urnieren- 
abschnitt ’). The part of the cardinals which lies anterior to the 
kidneys either disappears, or else gives rise to the azygos (and hemi- 
azygos) veils. 
In the Salamander, and apparently in most Urodeles, the right 
and left azygos are present normally, while in the greater number of 
Anura they disappear entirely in the adult. In Bombinator, how- 
ever, they persist (Gotte*, Hochstetter), and this is also the case 
occasionally in Alytes and Discoglossus *. 
Howes has recently described an interesting case of the persistence 
of the left azygos in a female of the Common Frog (Rana tempor- 
aria) *, the vessel being of large calibre and continuous anteriorly with 
1 «Beitriige zur vergl. Anat. u. Entwickelungsgeschichte des Venensystems 
der Amphibien und Fische,” Morphol. Jahrbuch, Bd. xiii. 1887-8. ‘*‘ Ueber die 
Bildung d. hinteren Hohlvene bei den Siugethieren,” Anat. Anz. ii. Jahrg. 1887. 
“ Beitrage zur Entwickelungsgeschichte des Venensystems der Amnioten,” 
Morphol. Jahrbuch, Bd. xiii. 1887-8. 
* Entwickelungsgeschichte der Unke. 
_ _ > GB. Howes, “On the Azygos Vein in the Anurous Amphibia,” Proc. Zool. 
Soc. 1888, p. 122. 
+ Loe. cit. 
