10 THOF. G. B. HOWES AND MR. H. H. SWINNERTON ON THE 



'J'he bottom of the vivarium was covered with coarse sand to a depth of about one 

 inch, and in one corner a Avater-bath was sunk; while a piece of corky-bavk was 

 introduced, which presented to the little captives a vaulted retreat. While to the 

 latter tlicy would readily retire, they exhibited a decided preference for the darker 

 recesses of the chamber. Their movements during the day-time were very active, the 

 passing of a finger-tip, the point of a pencil, or a piece of india-rubber tubing over the 

 glass front of their dwelling, being sufficient to entice them forward. The tendency to 

 burrow evinced itself during the second month — the actual date of the first efi'ort being 

 March 9th in one case observed. They exhibited a fondness for reclining in the water, 

 in which they would lie at full length, the top of the head being usually kept above 

 the surface. It was noticed that when, on leaving the water, the whole body was wet, 

 an area surrounding the pineal eye always remained dry ; and, concerning the use of the 

 " bath," it was observed that if an earthworm seized by the Lizard happened to be 

 beset by sandy particles, recourse was had to the water and a " washing " of it before 

 it was devoured. The prey was never swallowed as soon as seized, but always at first 

 held between the jaws and more or less masticated. 



The first ecdysis in the case of the largest specimen (T^'^- p. 5) was observed to take 

 place about March 9th, — i. e. about 7 weeks after hatching. 



Under the conditions above-described our little Sphenodons thrived and grew fat ; 

 ?. e. they increased in length during the four months we i\ept them alive from 8 cm. 

 to 15-17 cm. The near occurrence and manner of their decease, however (all three 

 having died in the "bath" within a period of 17 days), points to a common cause of 

 death. We suspect that this may have arisen from our having unconsciously con- 

 tinued to liberally feed them into the period normal to hibernation (April to middle of 

 August ^) ; but, on the other hand, it may have been the mere result of over-feeding 

 on our part (if indeed that may not have been in turn aided by the attentions of night- 

 watchers and others who were "interested"). Whichever be the case, the salient 

 feature of the dead animals was a superabundance of fat ; and we found jiost mortem 

 that this was evident externally in life, had we but known it, in the great enlargement 

 and tenseness — due to its accumulation — of the dorsal languets and certain irregular 

 folds of the skin originally described by Gray ^ ; i. e. that undue distension of these 

 may be an index of over-feeding — an observation to be borne in mind by those who 

 may yet be so fortunate as to rear this species in captivity. 



5. The Axial Skeleton. 

 General and as to Terminology. — The adult skeleton of Sphenodon has been so fullv 

 described in its modern aspects by Siebenrock (93) and Osawa (98 °) that recapitulation 

 of its general features is here unnecessary. Before, however, we proceed to details 



' Cf. Sfhauinsland. 98, p. 702 (for Stephen's Island). 

 " Cf. Graj, 42. p. 72. 



