206 MR. F. E. BEDDARD ON THE [Feb. 19, 



In a single example of Dromicia nana the azygos was well 

 developed on the left side of the body and there was a short 

 azygos on the right side. 



In a species of Pseudochirus the azygos was present on the left 

 side only ; in addition to the azygos an anterior intercostal flowed 

 separately into the vena cava anterior, deriving its blood fi'om a 

 single intercostal space only. In a second example {P. jie^'egrinus) 

 I found the same. The azygos proper commences with the second 

 rib and joins the vena cava in the neighbourhood of the left kidney. 



A single male example of Petaurus hreviceps, which was injected 

 to illustrate the anatomical relations of these veins, possessed an 

 azygos on the left side only. 



In the Thylacine the left azygos is the predominant one, and 

 there is also a left superior intercostal vein entering the precaval 

 independently of the azygos. The right azygos is, however, by 

 no means rudimentary for it supplies four intercostal spaces. 



Phascologale penicillata has likewise a well-developed azygos on 

 the left side extending back to the diaphragm. I saw none on 

 the right side of the body. 



In a female DasyurvjS viverrinus the azygos veins were almost 

 exactly like those of the Thylacine. The leftdiand vein was well 

 developed, extending back almost as far as the diaphi-agm ; on the 

 right the azygos was formed of five afiluents. In a male D. onaugcei 

 the left azygos was well developed and there was no trace of a 

 right-hand vein. 



A female Perameles ohesula agreed with Phascologale rather 

 than with the last species ; for the azygos was present only on 

 the left side of the body. 



Of 0>i?/cAo(/«Ze/re2tai« I have examined a single female example. 

 The azygos was predominantly developed on the left side of the 

 body. It flowed into the jugular at a point about opposite to 

 the fifth rib. The first branch of this left azygos formed the 

 intercostal vein lying between ribs 4 and 5. Thence regadar 

 branches were given off as usual. The main stem of the vein 

 became much thinner in the region of the diaphragm ; but there- 

 after increased notably in volume and could be traced back down 

 into the pelvic region as a massive vein of not much smaller 

 calibre than the vena cava, alongside and to the left side of which 

 it ran to a point which I did not determine. There is an obvious 

 similarity in this case to that of ^"Epyprymnus rufescens described 

 above. The azygos was connected to the vena cava by a stout 

 branch in the neighbourhood of the kidney. An anterior vein, the 

 superior intercostal, arose separately from the left jugular and 

 supplied ribs 3 and 4. There flowed into the right jugular 

 at a point corresponding to that of the left azygos a much 

 smaller right azygos. This slender vein only drew blood from ribs 

 4 to 7. 



The results obtained from the dissections enumerated in the 

 foregoing pages enable me to revise some of the conclusions 

 arrived at by Dr. McClure in his memoir referred to above. 



