THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY, 



[SECOND SERIES.] 

 No. 52. APRIL 1852. 



I 



XXI. — Notes and Descriptions of a few Brachiopoda ; including 

 a Monograph of the French Liasic Spirifers. By Thomas 

 Davidson, Member of the Geol. See. of France, &c. 



[With three Plates.] 



1. Observations on the Genus Rhynchonella of Fischer, with de* 

 scriptions of new species. 



For that group of plaited Terebratulce including such shells as 

 R. LoxicBy Fischer, Vespertilio, Brocchi, octopUcata, Sow., &c., 

 the generic names of Trigonella and Rhynchonella were proposed 

 by Fischer de Waldheim, in 1809 ; both genera comprise simi- 

 larly organized forms and are synonyms of each other ; and as 

 the name Trigonella had already been used by prior authors to 

 denote other objects, the term Rhynchonella alone can be ad- 

 vantageously preserved. The necessity of separating these shells 

 from the smooth Terebratulce was foreseen even by early natu- 

 ralists. Morton* in 1712 seems to have been among the first 

 to arrange his Terebratulce into two distinct divisions; in the 

 first he placed those species with a truncated beak ; and in the 

 second those in which the beak is acute and entire ; these divi- 

 sions corresponding the first to the genus Terebratula, the second 

 to that of Rhynchonella of modern authors. 



Davilaf in 1767 likewise alluded to the distinction between 

 these shells, and noticed the difiference in their apophysary 

 system ; but Fischer claims the honour of having first introduced 

 a distinctive appellation % . Within the last few years other genej'ic 



* Nat. Hist, of Northumberland, 

 t Catalogue systematique et raisonne. 



X Neglected however until 1847, when M. D'Orbigny re-established the 

 genus, giving the date 1825, being ignorant of Fischer's prior paper, of the 

 Ann. ^ Maj^. N. Hist. Ser. 2. Vol in. 17 



