THE BRITISH FOSSIL BRACHIOPODA. 375 



and the interiors of the larger number of them are still unknown, so that it is not yet 

 possible to class them all into really good and distinct genera ; still it is evident that some 

 attempt in that direction will have to be made. 



I have retained the genera Rhynchonella, Fischer, 1809 ; Rhynchopora, King, 1856 ; 

 JEatonia, Hall, 1857 ; J Dimerella, Zittel, 1870 ; s Atretia, Jeffreys, 1876 ; 3 and pro- 

 visionally, Terebratuloidea, Waagen, 1883. Dr. Waagen and M. (Ehlert would also 

 admit the genera Uncinulus, Bayle ; 4 Rhynchotrema, Hall ; 5 Rhynchonellina, Gemmellaro, 

 1871 ; 6 Acanthothyris, d'Orb, 7 and some others, which I am not yet prepared to admit. 

 One or two of them may perhaps be worth retaining. 



Dr. Waagen, at page 413 of his ' Salt-Range Fossils,' 1883, proposes a genus 

 Terebratuloidea for a Rhynchonella-shaped shell, in which he believes the beak to be 

 never entire, but always truncated and pierced at its end by a large oval foramen ; 

 while in true Rhynchonella, as is well known, the beak is pointed and entire, the foramen 

 being situated under its angular, incurved extremity. If this character is really demon- 

 strated to be constant, the genus Terebratuloidea should be retained. Unfortunately, 

 all the specimens of the genus that have passed through my hands for examination had the 

 extremity of their beak much worn. Dr. Waagen describes his genus Terebratuloidea as 

 being " more or less transversely oval or rounded, in its general appearance Rhynchonelloid 



1 'Twelfth Regents' Annual Report New York State Cabinet,' p. 35, 1869. Has no dental plates in 

 the ventral valve, a strong median septum in the dorsal valve, with four curved crura instead of two. 



2 ' Palseontographica,' vol. xviii, p. 220, 1870. A large area in the ventral valve, and a very high 

 and long septum in the dorsal one. 



3 " Preliminary Eeport of the Scientific Explorations of the Deep Sea in H.M.S. ' Porcupine,' " ' Proc. 

 Royal Soc.,' No. 121, p. 421, 1870; also Dav. ' Sup.' (vol. iv), p. 7, PI. I, figs. 7—10. 



* In his magnificent volume of plates, ' Explication de la Carte Geologique de France,' vol. iv, Atlas, 

 1878, Prof. Bayle proposes a genus Uncinulus for such shells as the Devonian Rh. sub-Wilsoni, d'Orb., 

 R. (Ehlerti, Bayle, Rh. imperatrix, Bayle, Rh. fallaciosa, Bayle, &c , but he gives no description of the 

 characters of his genus. At p. 690 of his ' Handbuch der Palaontologie,' 1880, Prof. Zittel alludes to a 

 genus Wilsonia, Quenstedt, but Dr. Waagen informs me that a genus Wilsunia was never proposed by 

 Quenstedt, and does not exist. Quenstedt speaks of " Wilsonier" ('Die Brachiopoden,' p. 193, 

 1871) as he speaks of " Bicorne?'," just as a collective name and never as agenus, and therefore, if we are 

 to admit a genus for similar species to those named by Prof. Bayle, the name Uncinulus would claim 

 priority. In the 'Annals and Mag. of Nat. Hist.,' 2nd ser., vol. ix, 1852, while treating of the genus 

 Rhynchonella I gave figures of the interior of both valves of true Rhynchonellte as well as of some of the 

 species which would be included in Bayle's Uncinulus, but I am not yet satisfied as to the necessity of 

 separating those species from Rhynchonella. In a letter to me M. (Ehlert expresses the opinion that 

 both Uncinulus and Eucharis, Barrande, may perhaps be good genera and worth retaining ; thus with time 

 it may be possible to add to the number of genera that should be comprised in the sub-family 

 Rhynchonellince. 



5 'Thirteenth Regents' Report New York State Cabinet,' p. 65, 1860. 



6 ' Studii Paleontologici : sulla fauna del Calcaris a Ter. janitor, ' iii, p. 29, 1871. Large area and 

 straight hinge-line, the dorsal valve with very long, sometimes bifid crura. 



7 'Annales Sci. Nat.,' xiii, p. 523, and 'Pal. Franc., Ter. Cretaces,' vol. iv, p. 343, 1850, for 

 Rh. spinosa. 



