RHYNCHONELLA. 



67 



I have, however, ventured to arrange our British specimens into thirty species, as seen 

 in the following Table, uniting at the same time, by a line, those forms more nearly 

 connected, a few of which may be only modifications of one great type. 



1. Rhyn 



chonella Wrightii. 







16. Rhyn 



chonella varians. 



2. 



— furcillata. 



17. 



— Forbesei. 



3. 



— rimosa. 



18. 



— serrata. 



4. 



— spinosa. 



19. 



— plicatella. 



5. 



— senticosa. 



20. 



— inconstans. 



6. 



— ringens. 



!-'■ 



— concinna. 



7. 



— subringens. 





r 1 22. 



— subconcinna 



8. 



— acuta. 







r23. 



— obsoleta. 



9. 



— cynocephala. 





" 



24. 



— subobsoleta. 



10. 



— variabilis. 



■ 



25. 



— angulata. 



11. 



— sub variabilis. 





1 26. 



— Morierei. 



12. 



— Lycettii. 







^27. 



— tetraedra. 



13. 



— oolitica. 







28. 



— subtetraedra. 



14. 



— Moorei. 





V. 



29. 



— lacunosa ? 



15. 



— Boucliardii. 







^30. 



— Hopkinsii. 



By simply glancing at the Table inserted at the end of this Monograph, we may perceive 

 how differently the types are distributed in the various subdivisions of the system. The 

 Inferior Oolite contains the greatest numerical amount of species and individuals ; in the 



ligament, or a short tube ; the smaller valve perforated, its summit not much produced, or recurved ; hinge 

 with . . . teeth. The Terebratulse with a perforated beak, therefore, form a very distinct family, the 

 Trigonella and the Rhynchonella being distinguished by their general aspect, and by their hinges, which 

 have not been, as yet, investigated." 



"27 Gros bee. The largest valve is that which, in other Terebratulse, is the smallest; has two teeth 

 and an arched contour. 



" Rhynchonella loxia Mihi. Valva major bidentata margine terminali in curvo. Tab. ii, figs. 5, 6, 

 loc. Talaroba. 



"Rhynchonella Canard, ' Ency.,' tab. 245, fig. 6 abc . 



" Rhynchonella Aigle, 'Ency.,' tab. 246." 



The first, R. loxia, he illustrates, and it is a well-known Oolitic species found abundantly in the neigh- 

 bourhood of Moscow, and resembling in general form R. acuta, but is a smaller shell with some other 

 differences, well figured by M. D'Orbigny in PI. xlii, figs. 22 and 25 of the ' Geol. of Russia,' under the 

 erroneous name of T. aptyca, a mistake corrected by the same author in his ' Prodrome.' 



All three are possessed of the same two short-curved appendages, as in T. psittacea. From the above, 

 it may be perceived that three of the types of Fischer's genus Trigonella, and his three Rhynchonellce are 

 similarly organised, and consequently belong to the same genus ; the one is synonymous of the other. 

 M. D'Orbigny having adopted the last, and judiciously placed in it a vast number of species, and this being 

 admitted by other authors, I will abide by the genus Rhynchonella, and place Trigonella as a synonym, 

 although, perhaps, that name ought to have been preferred, being first mentioned in the paper ; but it is 

 evident, that to bring about this most useless change, it would be necessary to re-shift all the species now well 

 known as Rhynchonellce, which in my opinion would be ridiculous, and in no way serving science ; later in 

 1830—37, Fischer notices Ter. acuta, Sow., Ter. ringens, V. Buch, and Ter. variabilis, Schl., as other 



