224 Transactions. — Zoology. 



cliians and the Sj^henodon, viz., a longitudinal axial perforation of the 

 vertebrae. 



Professor Seeley, in a series of most elaborate essays, compares the 

 bones of many living and extinct reptiles with each other. He finds that 

 " The abdominal ribs of Hatteria are like those of Plesiosaurus, and in one 

 species (for two species seem to me to be figured by Dr. Giinther) the 

 medium V-shaped bone is overlapped by a splice from a bone external to it. 

 In another species this is replaced by a joint, and the external piece has a 

 squamous expansion on the middle of its anterior and posterior margin, 

 unlike anything seen in Plesiosaurus. But, as in Plesiosaurus, other bones 

 are introduced between these elements, so as to make the abdominal ribs 

 nearly twice as many as the costal ribs."* He compares Ichthyosaurus and 

 Sphenodon thus : — " The apparatus of infracostal ribs seems caj)able of 

 being moved away with equal entirety in both groups, owing to the imion 

 of some of the elements by overlap."! Giinther thinks it most like the 

 Pihynchosaurus of the new red sandstone of Shropshire. 



Habitat. 



Until the last few years tuataras abounded in certain parts of the South 

 Island, especially on the banks of the Waimakariri river. About thirty 

 years ago four were caught on Mount Victoria, near Wellington ; one on 

 Somes Island in AVellington harbour ; and two by Mr. Mason, in the 

 Hutt Valley ; and in 1864 several were caught at Makara. They frequent 

 the sandy banks of rivers, and hide beneath fallen trees. They abound on 

 the Eurima Eocks, and on other islets in or near the Bay of Plenty, on 

 Motiti, and East Cape Island. Many were found on the Brothers Eocks in 

 Cook Strait during the recent erection of the lighthouse, but are now almost, 

 if not quite, exterminated by curiosity-hunters. On the large islands none 

 exist. Bush fires, wild pigs, dogs and cats, reptile-eating Maori tribes, and 

 the advance of civilization have swept away all of these strange creatures, 

 except the few which infest the tops of inaccessible rocky islets. Only one 

 of the islets forming the Brothers group, in Cook Strait, was inhabited by 

 them : this one was covered with loose sand and shingle, in which the 

 tuatara burrowed holes. The other two uninhabited islets are merely bare 

 hard rocks, affording neither food nor shelter. 



Habits. 



Tuataras grow very slowly ; young specimens have apparently not 

 increased in size during a whole year. A full-grown specimen must be 

 many years old. One is known to have lived out two generations of men. 

 Tuataras, like most rej)tiles, are very sluggish in their habits. They sleep 

 during the greater part of the day, coming out of their holes at night for 



* Joixr. Linn. Soc, XII,, 327. t Loc. cit., 399. 



