274 



IlARDWICKE'S SCIENCE-GOSSIP. 



genus Clisiophyllum " (pp. 81) ; and last, but largest 

 of all these intensely laboured productions, just issued 

 by the Glasgow Philosophical Society, a paper of 



the embryological development of each species of 

 coral, and the plates (some of which contain twenty 

 or thirty figures) give both transverse and longitudinal 



Fig. 172. — Zaphrentis." 



Fig. 174. — Histiophylhnn Beithianum. 



Fig. 173. — Ccntrophyllum subcaitriatm. 



two hundred and fifty pages, illustrated with fourteen 

 crowded plates, "On the Development and Generic 

 Relation of the Corals of the Carboniferous System 

 of Scotland." In the latter contribution Mr. Thom- 

 son has worked out, with the most admirable detail, 



Fig. 176. — A, Favosites ; B, Chajtotes. 



sections, showing gradual differentiation and increas- 

 ing complexity of structure. 



The whole of the herculean task ot personally 

 collecting, cutting (or superintending the cutting) ot 

 sections of every kind, something like twelve thousand 



