Reviews — Nicholson's Tabulate Corals. 



563 



accepts the Hydrozoal position of the first, and places the second in 

 the Zoantharia Aporosa, associating therewith in the same family the 

 recent genus Seriatopora. 



The family of the Favositidse, by far the largest and most impor- 

 tant group of the " Tabulata," is referred to the order of the Zoan- 

 tharia Perforata, and placed near the Poritidas. No fewer than 22 

 genera are enumerated in this family, of which 20 are Palaeozoic ; 

 one, KonincJcia, is Cretaceous ; and only one, Favositipora, Sav. 

 Kent, of recent age. The great development of this family occurs 

 in the Silurian and Devonian rocks, but few surviving into the 

 Carboniferous, and perhaps but one, Stenopora, passing into the Per- 

 mian. So important a part of the fauna of the Palasozoic age is 

 constituted by the genera of this family, that it will be of interest to 

 give a list of them : — 



Favosites, Lam. 

 Alveolites, Lam. 

 Yermipora, Hall. 

 Michelinia, De Eon. 

 Fleurodicti/um, Goldf. 

 Chonosteqites^. and H. (= Haimeophyl~ 



lum, Bill.) 

 Fachypora , Linds. 

 Striatopora, Hall. 

 Trachypora, E. and EC. (with Fendropora, 



Mich., and Rhabdopora, M'Coy.) 

 CceniCes, Eichw. 



Columnopora, Nich. 

 KonincJcia, E. and H. 



Favositipom, Sav. Eent. 

 ArcBopora, Nich. and Eth. jun. 

 Rozmeria, E. and H. 

 Syringolites, Hinde. 

 Nyctopora, Nich. 

 Ramingeria, Nich. 

 Stenopora, Lonsdale. 

 Billingsia, De Eon. 

 Laceripora, Eichw. 

 Nodulipora, Lindsti'om. 



It would occupy too much space to follow the author in his 

 exhaustive description of this and the other families, whose history, 

 characters and relations are treated ; all we can do is to refer briefly 

 to a few salient points. 



Dr. Nicholson includes in the genus Favosites the genera Calamo- 

 pora, Goldf. ; Emmonsia, E. and H.; and Astrocerium, Hall, all of 

 which have been based on characters too variable to allow of generic 

 distinction. 



In the comparatively new genus Pachypora. Lincl., 1873, of which 

 the more distinguishing feature, is the great thickening of the walls 

 of the corallites by a deposition of sclerenchyma, is included a 

 number of corals from the Silurian and Devonian of Europe and 

 America, which had previously been referred to Favosites, Alveolites, 

 and Cladopora, but have now been proved by microscopical exami- 

 nation to possess the peculiar characteristics of this genus. Micro- 

 scopical sections have also determined the Favositoid character of the 

 genera Striatopora and Trachypora ; in this latter genus the secon- 

 dary deposit of sclerenchyma in the corallites exists to such an 

 extent that it had previously been believed to be provided with a 

 dense coenenchymal structure surrounding the somewhat widely 

 separated apertures of the corallites. The genus Coenites, with its 

 peculiarly elongated calices, is also allied to Pachypora, and possesses 

 a similar thickening of the corallite walls. 



As respects the confusing genus Alveolites, the author concludes 

 that the presence of septal teeth as a generic distinction will have to 



