66 



INTRODUCTION. 



soon after becoming reflected. The double impressions of the adductor are seen on either 

 side near the mesial plate. 



Obs. The animal has been ably described by Professor Owen, and the pecuUar 

 arrangement and double attachment of the loop had been observed, and more or less accu- 

 rately figured, by several early naturalists, such as Griinther,' Davila,^ Favanne,' Martini, 

 Chemnitz,* Parkinson,^ Fischer de Walderm,^ and others; but it was only in 1835^ that the 

 apophysary system and animal were correctly represented. The form of the loop, as well 

 as the development of the mesial septum, varies in difierent species of Terebratella, as may 

 be seen in the annexed woodcuts. 



Fig. 9. 



Fig. 10. 



T. Evansii, Dav. 



7'. dorsata, Lamk. 



Geol. range. — Terebratella is not positively known in the Oolitic period, but the genus 

 is represented during the cretaceous epoch, and still continues to abound in our present seas, 

 where from ten to twelve species have been obtained.^ 



Exatnples: T. menardi, Lam., sp.; pectita. Sow., sp.; carantonensis, D'Orb.; canaliculata, 

 Roemer, sp.; dorsata, Lam., sp. ; flexuosa, King, sp. ; chilensis, Brod., sp. ; coreanica, Adam 

 and Reeves, sp. ; Bouchardii, Dav. ; rubicunda, Sow., sp. ; zelandica, Desh., sp. ; Evansii, 

 Dav. ; Sowerbii, King, sp. ; crenulata. Sow., sp. ; &c. 



the 'Synopsis of Carb. Foss. of Ireland,' p. 130, 1844, all I find there stated, is " Delthjridea, M'Coy, 

 fig. 27), or those species which have a long hinge line, and a distinct cardinal area (as in the DelthyridcB 

 or Spirifers), the deltidium fissured in the middle, all the species are largely plaited." No example is 

 mentioned, nor is the figure sufficiently illustrative to justify the author's claim to priority over 

 M. d'Orbigny, who clearly defined his genus in 1847. 



1 Naturforscher, 1774. 



2 Cat. Syst., pi. XX, 1767. 



3 La Conchyliologie, &c., pi. xli, fig. 13, 1780. 



* Systematische Conchylien, pi. Ixxviii, fig. 711, 1785. 



* Organic Remains of a former World, tab. xvi, fig. 7, 1811. 

 ^ Notice sur le Syst^me Apoph. des Ter., pi. i, fig. 34, 1829. 



'' Owen; Trans, of the Zool. Soc, vol. i, 2d part, pi. xxii, p. 141, 1835. 



^ For a list of the recent species, see Dav., 'Ann. and Mag. of Nat, Hist,,' May, 1852. 



