ANNIVERSARY ADDRESS OF THE PRESIDENT. Ixiil 



Argiope), exclusively I'pper j.Iesozoic (as ^lagas), or exclusively re- 

 cent (as Bovchardia, Kraussia, and Morrina). 



Strinyocepfialus follows as the type of a piovisional family, exclu- 

 sively Devonian. 



The Tkecididce, represented by Theeidium alone, range continu- 

 ously from the Trias to the present time. 



Tne Spiriferidce concentrate towards the palseozoic pole. In this 

 family Mr. Davidson includes Splrifer (with Spnnferiaa and Cyrtia 

 as sections), Athyris, ^pinyera, TJndtes and Atrypa. 



Rhynchonella, with Camerojjhoria and Pentamerufs, form a family 

 under the name of Rhy/ichonellidcB. The absence of perforations in 

 the shell is the rule in this group. The typical genus is one of the 

 Hnks between the palseozoic and present epoch, and has its maxi- 

 mum in the Mesozoic. 



The Strojjkrrmenidce, ProdvMidcE, and Calceolida all concentrate 

 in the Palaeozoics ; Leptckna only, in the first named family, extending 

 into the lower Jurassic strata. 



In the Craniadce, represented by the single genus Crania, we 

 have a type of Brachiopod almost equallv present at all epochs. The 

 nearly alhed group of Liscinid^e, though extending to the present, 

 is generically concentrated in the Lower Palseozoics. The same re- 

 mark may be made respecting the Lin(jvhd<e. 



Accepting the genera adopted by Mr. Davidson as mutually 

 equivalent groups, and regarding their distribution in time as deter- 

 mined by tdm from a vast amount of specific materials, enough to 

 induce us to believe that future discoveries will not materially disturb 

 any inferences drawn from the numbers as now presented to us, then 

 we arrive at several striking conclusions concerning the entire sub-class. 

 Regarding the Present and the Lower Paleeozoic epochs as oppo- 

 site poles of time, we find the generic types among the Brachiopoda 

 concentrate as it were around or towards each, whilst they depauperate 

 towards the equatorial region of the scheme, about -nhich indeed no 

 generic types originate. The loop-armed types are regnant, as it were, 

 anteaUy, the spiral-armed types posteally ; and the latter are in the 

 main so dominant, that the Brachiopoda, as a great assemblage of 

 types, has its major development towards the past, its minor towards 

 the present, and its zero in the parting epoch between the palEeozoic 

 and after-ages. 



Some special memoirs on fossil Brachiopoda may here be noticed. 

 Mr. Davidson has communicated an excellent tabular view of the 

 classification and distribution of the genera to the ' Bulletin ' of the 

 Geological Society of France; and in our own Journal he has described 

 and figured a number of species from the Devonian rocks of China, a 

 region where some future palaeontologist is likely to reap a rich palte- 

 ozoic harvest. The remarkable discoveries in the lias of our own 

 country by Mr. ?\Ioore of Ilminster, have found a parallel in France, 

 where M. Eugene EuJes-Deslongchamps, who promises to be worthy 

 of the distinguished name of his father, has found numerous species 

 of Leptcena and Theddea in the Liassac beds of several localities in 

 Calvados. His essay, amply illustrated, forms part of the newly 



