76 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Juiie 14, 



vation, were not fully expanded ; yet many of them are given by au- 

 thorities sensible of the necessity of caution in that respect ; and it is 

 well known that those appendages vary greatly in their characters, 

 and are frequently very short or obsolete. This inquiry must not be 

 pursued further, but sufficient has been advanced to show, that there 

 is not an absolute agreement between lamellae and tentacula ; and 

 therefore that it is not safe to reason from one structure to the other 

 in considering the place of an extinct coral in a systematic arrange- 

 ment. If, however, attention be confined to Tuhipora, still, as before 

 remarked, it would be palpably wrong to assume, that a fossil, pos- 

 sessed of peculiarities totally wanting in the recent zoophyte, should 

 have had the same number of tentacula as that body; and still more 

 so, that those appendages, whatever may have been their amount, 

 should have had a similar conformation and distribution. From esta- 

 blished extinct genera, little assistance also can be obtained, though 

 they have had definite positions assigned them. Catenipora is known to 

 have twelve furrows*, and Syrincjopora has more than that number-f; 

 and such grooves are generally considered as representatives of la- 

 mellse ; the difference depending on the membranes, which connected 

 the digestive sac with the sides of the cavity, not having been pro- 

 vided with secreting vessels. The Chcetetes of M. Fischer | has 

 neither rudiments of lamellae nor furrows, but the fissiparous manner 

 of producing additional hollows for the reception of digestive organs, 

 clearly forbids its being regarded as allied to Choristopetalmn. Eliren- 

 berg states, from actual inspection, that the Calamopora Gothlandica 

 of Goldfuss (Favosites id. of Lamk.) has from six to twelve interrupted 

 lamellae (Beitrilge, p. 122). No such points or papillae have been 

 hitherto noticed by the author of these remarks in a coral, believed to 

 be specifically identical with that described and figured by Fougt§, 

 and quoted by Lamarck ; though in British and foreign palaeozoic 

 fossils, allied to a variety of Goldfuss's Ca/. basaltica (Petref. pi. 26. 

 fig. 4 a) and Cal. alveolaris (fig. 1 c, same pi.), they are very con- 

 spicuous, but in many cases far exceed the number mentioned by 

 Ehrenberg ; and they are often not reducible to definite series. Fully 

 admitting, nevertheless, the accuracy of his observation, still Calamo- 

 pora, as retained by him, cannot be considered simply as a 12-radiated 

 genus; its whole characters moreover being open to investigation; 

 but, whatever may be its true systematic position, no aid can be de- 

 rived from its composition in determining that of the lower green- 

 sand zoophyte II . Lastly, the Alveolites of Lamarck (op. cit. p. 285), 

 assuming Alv. suborhicularis as the generic type, wants apparently 

 all equivalents for lamellae (consult Goldfuss, pi. 28. fig. 1); but the 



* Ehrenberg, Beitrage, p. 120. 



+ De Blaiuville, Man. d'Actinol. p. 353-354 ; also Geology of Russia by Sir 

 11. Murchison, M. de Verneuil and Count Keyserling, vol. i. Appendix A. p. 591. 



X Oryctographie du Gouvernement de Moscou, p. 159, 1837. 



§ Dissertatio de Coralliis Balticis, Amoen. Acad. vol. i. p. 211, plate, fig. 27, 1745, 

 edit. 1749 ; Lamarck, 2nd Edit., tome ii. p. 320. 



II It is impossible in this notice to discuss the distinctive characters of the 

 fossils composing M. Goldfuss's Calaraopora, as a full investigation of them would 

 occupy very many pages. 



