1908.] ANTECHINOMYS AND OTHER MARSUPIALS. 573 



I found this membrane, and I may take this opportunity of 

 remarking that the omentum also is attached, though for a very 

 shoi-t space, to the colon as in the genus Macrojms. Neither 

 of the facts is represented in Klaatsch's figure of the gut 

 of Trichosurus vidjyecula *. There remains, however, a sub- 

 stantial difierence between Trichosurus and Pseudochirus on 

 the one hand and Macropus on the other, in that in the latter 

 the connection between omentum and colon is extensive, as is 

 duly figured by Klaatsch for Macro2yus hennettii. I cannot 

 agree with Dr. Mitchell in finding no connection of this kind 

 between the duodenum and colon in Hyrax. In examples of 

 this " Subungulate " which I dissected some time since, the 

 duodenum near to its exit from the stomach was adherent to 

 the colon in the neighbourhood of (distal to) the paired cfeca by 

 a ligament of some length. Moreover, there was also a fixation 

 of the omentum upon the same region of the colon. I take 

 this opportunity of remarking that Hyrax shows a particular 

 point of likeness to the Perissodactyle Ungulates as I venture 

 to think. In the latter group without exception, as has been 

 shown by many anatomists, the cfecum is immediately followed 

 by a single simple loop of the colon. The same occurs in Hyrax^ 

 though it is in that animal not quite so well-marked. The 

 colon immediately after leaving the single caecum, which I regard 

 as the equivalent of the Perissodactyle caecum, is folded back 

 along the caecum and connected with it by a ligament ; the distal 

 limb of this loop is not quite so well estab)lished as in the 

 Perissodactyle, however. I discuss these facts more in detail on 

 a subsequent pagef. 



The attachment of the great omentum to the colon is well- 

 known as an anatomical fact. Klaatsch has figured this in 

 several forms. Later in this communication I direct attention 

 to the same attachments in various Rodents and Lemurs. 



1 have found no such attachment in Carnivora J, nor in 

 American Edentates (in which I am in accord with Klaatsch). 

 In Oryctero'pus, however, — and this emphasises the distinctness of 

 that type from its alleged relatives in the New World — there is 

 a fixation of the omentum along two separated lines. The most 

 anterior is on to the caecum and the vei-y commencement of the 

 colon. Then follows a considerable area of colon unattached to 

 the omentum which is again attached to it further along. This 

 state of affairs reminds us of the transitory condition in the 

 human foetus figured by Klaatsch [cf. loc. cit. p. 694, fig. 16), 

 which is, however, permanent in Cebus as he has pointed out. 

 For other facts relating to the attachment of the omentmn and 

 of other ligaments reference may be made to subsequent pages, 

 where they are described in several animals. 



* Loc. cit. pi. xxii. fig. 7. t See below, p. 579. 



X Except ill one or two cases where it appeared to me to be distinctlj' patbolog-ical. 

 The noii-attachment of the omentum in Carnivora is not, of course, put forward as 

 a new fact. I confirm it by fresh instances. 



