94 Transactions. — Zoology. 



in colour in the several islands or groups of islets which it in- 

 habits. With the exception of a green form, exhibiting some 

 structural modifications, which I have dedicated to our great 

 herpetologist, under the name of Sphenodon gucntheri, it has 

 been found impossible to distinguish these forms except as 

 local varieties, sufficiently well marked however to admit of 

 their being referred to their respective island habitats. What 

 are these, I would ask, but incipient species ? Allowing suffi- 

 cient time under the existing conditions of life, and, reasoning 

 by analogy, each island or group of islets must in the end 

 possess a distinct species of Sphenodon exactly suited to its 

 ■environment. It is, moreover, sufficiently clear that nothing 

 but the island asylum could have saved this lowly-organized 

 and archaic form from absolute extinction. * 



Less fortunate has been another form of New Zealand 

 lizard, the Kawekaweau, whose quasi-arboreal habits of life 

 have prevented its taking advantage of this last refuge. From 

 the accounts of the natives, the Kawekaweau appears to have 

 been a form of iguana inhabiting the deep forest, and there 

 can be no doubt that it lingered in the land till within 

 the last thirty years, when the remnant of its race suc- 

 cumbed to wild pigs and other natural enemies. It is always 

 described by the Maoris as beautifully marked with alternate 



* I may here remark that one is surprised to find a naturalist like Mr. 

 H. 0. Forbes — fresh from New Zealand, and with all the literature on the 

 subject at his command— in his recent address to the .Royal Geographical 

 Society, referring to the Tuatara as " a curious and ancient form of lizard 

 now absolutely confined to an islet off the coast of the North Island." 

 Here is a statement of fact, made with apparent scientific accuracy, and 

 yet far wide of the truth. It is quite true that the tuatara has become 

 extinct on the mainland, but it still exists in considerable numbers on the 

 rocky islands adjacent to our coasts. It is common on the Hen and 

 Chickens, on Cuvier Island, on the Poor Knights, on the Mercury Islands, 

 and on the Barrier Islands, in the Hauraki Gulf. Coming further south, it 

 is abundant on the Alderman Islands, on Motunau or Plate Island, on the 

 Island of Karewa in the Bay of Plenty, on the Rurima Rocks, on Whale 

 Island, and on East Cape Island. It inhabits the various groups of islands 

 in Cook Straits, such as Stephen Island, the Brothers, and the Chetwynd 

 Islands. It has been recorded from other localities; and it is highly 

 probable that it exists on many unexplored islets or rocks lying off the 

 coast of the North Island. The last recorded specimen from the main- 

 land was ca,ptured in Evans Bay about the year 1842, and was preserved 

 by Dr. Monteith, one of the early Wellington settlers. He presented it to 

 me some twelve years later, and it is now in the collection of the Colonial 

 Museum. The extermination of this lizard is attributed to its natural 

 enemies of modern times, pigs and rats, whose ravages it has hitherto 

 been able to escape on the small uninhabited islands. Unfortunately, of 

 late years even there it has been exposed to the persecution of travelling 

 natural-history collectors, one of whom is said to have forwarded at 

 one time to Europe no less than three hundred specimens preserved in 

 spirits. 



