56 MR. F. E. BEDDARD ON THE ANATOMY [Jan. 15, 



(5) So7ne new Facts hearing tipon the A^nities of 

 Gei'rlionotns. 



This genus of Lacertilia is sometimes placed in a special family 

 of Lacertilia, the Gerrhonotidfe. By others (e. (/., Boulenger *, 

 Gadow t) it is relegated to the Anguidfe. The general aspect of 

 Gerrhonottos cceruleus is, on the other hand, by no means unlike 

 that of the Scincidte ; I am not aware that any notes have ever 

 been published upon the visceral anatomy of this Lizard. I 

 venture, therefore, to lay before the Society some notes which a 

 recent dissection of more than one example of Gerrhonotus cceruleus 

 enables me to offer as a contribution towards the determination 

 of the systematic position of this genus oi- representative of a 

 family. 



I have by no means attempted an exhaustive survey of the 

 anatomy of this Lizard. But I am able to note down a few facts, 

 all of which are of some interest from the point of view of a 

 comparison with other Lacertilia. The structure of the quadrato- 

 jugal ligament is one of the characters which I carefully examined 

 in Gerrhonotus. I find that the arrangement and appearance of 

 this ligament is precisely as it is in the genus Gerrhosaurus and 

 in the Skink Eumeces J. That is to say, the ligament of this 

 genus is very distinctly marked off and of equal breadth through- 

 out, nowhere vaguely shading off into surrounding tissues. 

 Moreover, it is attached on the one hand, of course, to the quadrate 

 bone and on the other to the bony scales which cover the face in 

 this region. It is not inserted on to any bone of the skull. In 

 the present state of our knowledge it is not possible to comment 

 upon this likeness to Gerrhosaiirus and Eumeces as an argument 

 in favour of the Skinkoid affinities of Gerrhmiotus, though I have 

 thought it woi'th while to record the fact for future comparison. 

 The second feature in the structure to which I draw attention is the 

 complete pigmentation of the interior of the body. There is here 

 no paler area divided by the oviducal mesentery from a moi-e 

 darkly pigmented posterior portion. 



As is now well known §, the umbilical ligament of the Skinks 

 is frequently a double ligament attached to the ventral surface 

 of the liver along two parallel lines which become confluent 

 anteriorly. I observed nothing of the kind in Gerrhonotus, where 

 the umbilical ligament is, as in most Lizards, a single mesentery. 

 In this anatomical fact there is a likeness to Ophiosaurus as well 

 as, of course, to Iguana and other Lizards. In any case the Lizard 

 shows no affinities to the Scincidse. 



The pancreas and the spleen and their relationship to one 

 another differ greatly among the Lacertilia, and more than one 

 fact in the structure of the two glands is recorded in the present 



* Catalogue of Lizards in the Collection of the British Museum. 

 f " Reptilia," in ' Cambridge Natural Historj',' p. 538. 

 + P. Z. S. 1905, vol. ii. p. 256. 

 § Beddard, P. Z.S. 1888, p. 102. 



