264 



Lamarck's Genera of, Shells. 



Fig- 



217. Renulites opercularis. [Ency. 



PI. 465. Fig. 8.) 



218. Cristellaria squammula. a. nat. 



size. {Fichtel. PI. 16.6.) 



219. Orbiculina numismalis. a. nat. 



size. b. transverse section, 

 shewing the chambers, c. side 

 view, shewing the aperture. 

 {Fichtel. PI. 21. a. b.c.d.) 



220. Miliolites coranguinum. {Ency. 



PI. 469. Fig. 2. a. b.) 



221. Melonites sphsrica. a. nat. size. 



Fiihtel. PI. 24. b.) 



222. Rotalites trochidiformis. upper 



and under side. 



223. Lenticulites rotulata. {Ency. 



PI. 466. Fig. 5.) 



224. Placentula pulvinata. a. nat. size. 



(Fichtel. PI. 3. 6.) 



225. Discorbites vesicularis. {Ency. 



466. Fig. 7. a.) 



226. Siderolites calcitrapoides. a. nat. 



size. b. transverse section. 

 {Fichtel. PI. 15. e. k.) 



227. Polystomella crispa. a. nat. size. 



b. side view. c. transverse sec- 

 tion. {Fichtel. PI. 4. d. e. f. 

 and PI. 5. b.) 



Fig. 

 228. 



229. 

 230. 

 233. 



232. 

 233. 



234. 



235. 

 236. 

 237. 



238. 



239. 



Vorticialis craticulata. a. nat. 



size. b. side view. {Fichtel. 



PI. S.h.i.k.) 

 Nummulites laevigata. 

 Nautilus pompilius. 

 Ammonites Konigi. {Sowerbt/s 



Min. Con. No. 46. PI. 263. 



Fig. 3.) 

 Orbulites subradiata. 

 Ammonoceratites glossoidea. 



(Bomlich. PI. 3. Fig. 14.) 

 Turrilites costulata. {Sowerby's 



Min. Con. PI. 36.) 

 Baculites Faujasii. 

 Argonauta Argo. 

 Loligo vulgaris — the corneous 



lamina very much reduced. 



a. b. cranium — nat. size. c. the 



beaks united, d. e. its parts 



separate — ■/. indented ring of 



the sucker. 

 Sepia officinalis, the shell very 



much reduced, a. beak. b. 



sucker ring. c. egg. All nearly 



the natural size. 

 Carinaria vitrea. {Ency. PI. 464. 



Fig. 3.) 



c :■::- :o:o:co- :oy>zozo 



ERRATA. 



Vol. xv. p. 219, line 26, for " air-holes," read " suckers." 

 Vol. xv. p. 248, line 8, for " nerita," read " nutica." 



Art. VII. Experiments on the Proportion of Charcoal ob- 

 tained from Woods having a greater Specific Gravity than 

 Box. By Mr. T. Griffiths. 



The pieces of wood, having their respective weights carefully 

 taken, were put into crucibles covered with sand, which were 

 placed in a strong heat, till all the volatile products were dissi- 

 pated. The charcoal thus obtained was weighed whilst warm, in 

 cider to prevent any inaccuracy that might have been occasioned 

 by the absorption of moisture from the air. Of the many different 

 woods that might have been employed, eight specimens have been 

 selected, and the result of the experiments made upon them, are 



