Zoological Society. 441 



surface representing that of new woody wedges in the axis, the 

 transverse marks left by the successive stages of upward growth, all 

 indicate that at least several years must have been required for the 

 growth of stems of moderate size. The enormous roots of these 

 trees, and the conditions of the coal-swamps, must have exempted 

 them from the danger of being overthrown by violence. They 

 probably fell, in successive generations, from natural decay ; and, 

 making every allowance for other materials, we may safely assert 

 that every foot of thickness of pure bituminous coal implies the quiet 

 growth and fall of at least fifty generations of Sigillarice, and there- 

 fore an undisturbed condition of forest-growth enduring through 

 many centuries. Further, there is evidence that an immense amount 

 of loose parenchymatous tissue, and even of wood, perished by decay ; 

 and we do not know to what extent even the most durable tissues 

 may have disappeared in this way ; so that in many coal-seams we 

 may have only a very small part of the vegetable matter produced. 

 Lastly. The results stated in this paper refer to coal-beds of the 

 middle coal-measures. A few facts which I have observed lead me 

 to believe that in the thin seams of the lower coal-measures remains 

 of Noeggerathia and Lepidodendron are more abundant than in those 

 of the middle coal-measures*. In ihe upper coal-measures similar 

 modifications may be expected. These differences have been to a 

 certain extent ascertained by Goeppert for some of the coal-beds of 

 Silesia, and by Lesquereux for those of Ohio ; but the subject is 

 deserving of further investigation, more especially by the means pro- 

 posed in this paper, and which I hope, should time and opi)ortunity 

 permit, to apply to the seventy-six successive coal-beds of the 

 South Joggins. 



ZOOLOGICAL SOCIETY. 



July 27, 1858.— Dr. Gray, F.R.S., V.P., in the Chair. 



Description of Riama, a New Genus of Lizards, forming 

 A distinct Family. By Dr. John Edward Gray, F.R.S., 

 F.L.S., V.P.Z.S., Pres. Ent. Soc. etc. 



Mr. Louis Fraser has lately sent to the British Museum a con- 

 siderable series of Lizards, Snakes, and Toads and Frogs from Gua- 

 yaquil, in spirits. Among other interesting species is an annulated 

 Lizard, which, as it cannot be referred to any of the existing families, 

 and has a very peculiar external appearance, must at the same time 

 be considered as the type of a new genus and new family. 



This Lizard belongs to the section o^ Cyclosaurce, which have a 

 distinct longitudinal fold along each side like the Zonuridce ; but it 

 differs from the animal of that family in all the scales of the body 

 and tail being elongate, four-sided, placed in transverse rings and 

 regular longitudinal series, like the scales of the AmphisbcenidiB, while 



* I may refer to my late paper on Devonian Plants from Canada for an exam- 

 ple of a still older coal made up principally of remains of Lycopodiaceous plants 

 of the genus Psilophyton, 



