442 Mr. T. Davidson on Lamarck's species of 



38. Terebratula tetraedra (Sow. M. C. tab. 83. fig. 4). 



Obs. The specimens attributed to this species in Lamarck's 

 collection do not belong to Sowerby's type, but to that beautiful 

 and well-characterized species known under the name of Tere- 

 bratula decor ata, Schloth., so admirably illustrated and described 

 by M. Le Vicomte D'Archiac in the * Mem. de la Soc. Geolo- 

 gique de France/ and also well represented in pi. 244. fig. 2. of 

 the f Encyclopedic Methodique.' Lamarck, singular to say, had 

 in his collection specimens of Sowerby's type, but which he 

 places in his Terebratula spathica. 



39. Terebratula plicata, Val. in Lamk. PI. XIV. fig. 39. 



T. testa subtetraedra, subgibbosa, plicata, non sinuata : 5 vel 6 costis 

 ab umbone obtusis, et ad marginem angulatis : nate brevi. 



Obs. Lamarck or Valenciennes refers to the 'Encyc. Metho- 

 dique/ pi. 243. fig. 11 and pi. 244. fig. 1, and states that his 

 species approaches the preceding one : but the absence of a sinus 

 forcibly distinguishes it. This species is well characterized, 

 and seems to belong to the liasic beds of the north of Italy. 

 There exist, besides the two specimens described by M. Valen- 

 ciennes, in the Garden of Plants, a number of fine specimens from 

 the collection of the Marquis de Dree. In B. Delessert's collec- 

 tion we also find two specimens labeled Terebratula plicata var., 

 which however belong to the Inoceramus sulcatus and to the 

 Pecten quinquecostatus. Lamarck's Terebratula plicata being a 

 good species should be retained. Mr. Buckman was not aware 

 of Lamarck's priority when he attached a similar name to 

 another species. M. D'Orbigny in his ' Prodrome ' has given 

 to Mr. Buckman's shell the name of Terebratula subplicatella, 

 D'Orb. 1847, which however he had no right to do according 

 to his views, because Lamarck's species not being a true type 

 of the genus Terebratula, would be placed by him in the genus 

 Hemithyris or some other of his proposed genera, while Mr. Buck- 

 man's Ter. plicata might then remain in the Terebratulas. La- 

 marck's species varies in the number of plaits on the mesial fold ; 

 some specimens present four plaits, others five, and in a few spe- 

 cimens two plaits unite into one towards the margin of the shell. 



40. Terebratula canalifera, Val. in Lamk. PL XIV. fig. 40. 



T. testa trigonata, gibba, longitudinaliter sulcata, sinuata, cardine 

 recto : nate declivi. 



Obs. The Terebratula canalifera of Lamarck belongs to the 

 genus Spirifer, and reference is made to pi. 244. fig. 4, 5 and 6. 

 of the ' Encyclopedic Methodique :' fig. 5, which appears to be 

 the type, and is a well-known Devonian species from Paffrath 



