CORBULID^. 43 



power of complaint ; and all that can be said of them is 



Sic vos non vobis saxa forate diu. 



It constitutes the type of Meurian de Bellevue's genus 

 Rupicola. Pennant and Donovan described it as Venus 

 sinuosa, Lamarck as Anatina rupicola, Philippi as Ery- 

 cina anodon, Anatina ? pusilla, T. ovalis, T. fabula, and 

 T. elongata, Recluz as Rupicola concentrica, and Des- 

 hayes as T. brevis. Many other species have been made 

 by Reeve from Mr. Cuming's specimens of this ex- 

 tremely variable shell. It appears to have been con- 

 founded by Kiener with T. corbuloides, Deshayes, on 

 the supposition that it was a smaller form of that 

 species. 



Another species of Thracia (Amphidesma truncata, 

 Brown, or T. myopsis, Beck) has been found in glacial 

 beds, at Greenock by Mr. Stewart Kerr, and at Elie in 

 Fifeshire by the Rev. Thomas Brown. To this species 

 appears to have also belonged a shell named " Cochlo- 

 desma, n. s." by Professor King, which was lately 

 brought up from the depth of 1000 f. or thereabouts, 

 100 miles west of Cape Clear, by Capt. Hoskyn in 

 H.M.S. ' Porcupine '; and the fragments of which I 

 have examined. T. myopsis now lives only in the 

 Arctic seas. 



Family XIX. 

 CORBU'LIDJE, (CORBULADJE) Fleming. 



BODY oval or globular : tubes short and united ; excretal tube 

 furnished with a conspicuous valve : foot long and flexible. 



SHELL oval, more or less inequivalve and open at the pos- 

 terior end : beaks turned towards the posterior side : cartilage 

 wholly internal, occupying a horizontal triangular cavity under 

 the beak in each valve : hinge strong, furnished in some genera 



