1 4 MR. F. E. BEDDARD ON THE [Jan. 1 7, 



The umbilical ligaments of Amphiholurus are moi^e like those 

 of Physig7iathus than those of Chlamydosatirus ; but the con- 

 ditions observable are at the same time somewhat intermediate 

 between those in the other two. The umbilical ligament divides, 

 as in Physignathtis, before the posterior end of the liver, but 

 rather nearer to the end than in that genus. In Chlcmiydo- 

 scmrus the conditions are not really different ; it presents us 

 merely with the third term in a series, for the umbilical ligament, 

 as mentioned, arises as one sheet from the liver up to the 

 very point of its bifurcation into two lobes ; it then follows 

 both, leaving the gall-bladder between. In Physignathus a tiny 

 fragment is cut off each of the two lobes of the liver, and these 

 lie between the tent-like folds of the posterior region of the 

 umbilical ligament. Finally, in Amphiholurus a large piece of 

 liver-substance belonging to the left lobe as well as a small piece 

 belonging to the right lobe, in addition, of course, to the gall- 

 bladder, lie sheltered by the posterior divided region of the 

 umbilical ligament. As in Chlamydosaurus, no muscular layer 

 passes out upon the liver. 



It is plain, therefore, that in these characters Chlamydosaurus 

 does not stand markedly apart from its allies. The liver, however, 

 is rather more compressed and not quite so broad from side to 

 side as in Physignathus and Amphiholurus, especially in Amphi- 

 holurus. In all these genera the long prolongation of the right 

 lobe (the " Hohlvenenfortsatz " of Hochstetter) extends right 

 down to the testis of its side of the body. There is no great 

 length of vena cava left between testis and liver such as exists in 

 some lizards, e. g. Tiliqua. In the Agamidee, moreover, there is 

 not always so marked a prolongation of the liver-lobe towards the 

 gonad ; for while in a $ Agama colonorum the liver-lobe was 

 nearly in contact with the ovary, there was in a $ Uromasiix 

 acanthinur^is a considerable sti'etch of vena cava between the 

 two. 



Mesenteries of Colon. — In Uromastix acanthinurtis, which is a 

 vegetable-feeder, the large intestine is particularly long, and the 

 wide colon with thin greenish walls is sharply to be distinguished 

 from the naiTOW thick-walled rectum. The whole of the colon 

 and the greater part of the rectum lie outside of the shelter of 

 the pelvic bones. In these particulars Uromastix contrasts with 

 Physignathus. 



Associated with this is a peculiarity in the arrangement of the 

 mesenteries which is so far peculiar to the genus. In addition to 

 the median dorsal mesentery tying down the gut to the parietes, 

 the colon has a second mesentery which affixes it to the elongated 

 process of the right lobe of the liver and to the vena cava behind 

 the point where the lobe of the liver ends. This membrane forms 

 the mesorectum at the beginning of the rectum, but it is distinct 

 from it, as is shown by the fact that it is not pigmented, while 

 the mesoi-ectum is, and that its muscular fibi-es ai'e more abundant 

 and larijei'. 



