BEACSIOTODi.. 



365 



Fi>. 151. Terebratella. 



fathoms. Fossil, 90 species. Carb — . Soutli America, Europe. 

 Eudesia (carclium), Eng, includes 1 recent and 6 fossil species 

 which, are sharply j)laited. T. impressa (PL XY., Pig. 5) is 

 the t}^^ of a group which has the external shape of TerehrateUa. 

 Meganteris, Suess, 1856. Terebratula Archiaci, Vern. JDevo- 

 nian, Asturias. Shell with a long, reflected, internal loop, 



Terebratella, D'Orbigny. 



Type, T. dorsata, Gmel. (= Magel- 

 lanica, Chemn.) PI. XY., Fig. 7. Fig. 151. 



Shell smooth or radiately plaited ; dorsal 

 valye longitudinally impressed ; hinge- 

 line straight, or not much curved; beak 

 with a flattened area on each side of the 

 deltidium ; foramen largo ; deltidium in- 

 complete; loop attached to the sej^tum (s). 



Animalli^Q Terehratida ; the spiral lobe 

 of the brachial disk becomes very 

 diminutiye in some species, and is 

 obselete in Morrisia and T. Ciuninrjii. 

 Distrihution, excluding sub-genera, 

 25 species. Cape Horn, Yalparaiso 

 (90 fathoms), New Zealand, Japan, 

 Ochotsk, Spitzbergen, Labradoi\ 

 Fossil, 16 species. Lias — . United 

 States, Europe. In T. cremdata and Evansii (Fig. 152) the 

 dorsal septum sometimes jirojects so far as to touch the opjDO- 

 site valye, but in other examples it remains undeveloped. 

 (Davidson.) 



Suh-genera. Trigonosemus (elegans), Kcinig. Sijnonyms, Del- 

 thyridcea (pectiniformis), M'Coy. Fissirostra, D'Orbigny. 

 Example, T. Palissii, PI. XY., Fig. 8. Shell finely plaited, 

 beak prominent, curved, with a narrow apical foramen ; cardinal 

 area large, triangular ; deltidium solid, flat ; cardinal process 

 very prominent. Distribution, 5 species. Chalk, Europe. 



Lyra (Meadi), Cumberland, Min. Con. 1816. PI. XY.,Fig. 6. 

 Synonyms, Terebrirostra, D'Orbigny. Ehynchora, Dalman.* 



* The name Rhynchora was given by Dalman to the Ter. costata. Wahl. — T. 

 pectinata, L.) on the supposition that it was identical with Sowerbj^'s T.Lyra; and 

 as no specimen could be found with a long beak, an artificial one was manufactured 

 for it, of which there is a cast in the British Museum. The second species of " RhjTi- 

 chora," Ter. spatulata, Wahl., has no beak whatever: in shape it is like an Argiope., 

 but measures an inch each waj'. The ventral valve is a simple bent plate with the 

 teeth at the angles ; the dorsal valve is flat, with a veiy wide hinge-plate, and sockets 

 "Jt the angles, whilst a single septum projects from the centre, with portions of a Itxi^' 

 tttached. 



Fig. 152. Ter. Evansii, Dav. 



