576 MAGASINiE. 



Sub-fam. MAGASINiE. 



Shell smooth or radiately plaited ; dorsal valve with a 

 longitudinal depression ; hinge-line straight or only slightly 

 curved ; area usually distinct ; deltidiuni frequently incom- 

 plete. Loop attached to the septum of the dorsal valve. 



Genus TEREBRATELLA, D'Orbigny. 



Shell with the loop elongated, reflected, doubly attached, 

 once to the hinge-plate and again to the longitudinal septum, 

 by processes given off at right angles from the crura near 

 the centre of the valve. 



Syn. Delthyris, Mke. 



Ex. T. dorsata, Gmelin, pi. 180, fig. 4, 4, a. 



In this genus the loop is long and doubled upon itself 

 as in Wahlhcimia, but the crura give off about their middle 

 a flat, wide, horizontal process which is affixed to the 

 elevated, longitudinal, central septum ; there are fourteen 

 recent species of Terebratella described, from all parts of 

 the world. In the sub-genus Waltonia, which is founded 

 on a single minute specimen, the reflexed portion of the 

 loop is wanting, but this may possibly have been broken 

 away. 



Species of Terebratella. 



Bouchardii, Davidson. flexuosa, King. 



Chilensis, Brod. frontalis, Midd. 



Coreanica, Adams and Reeve. Labradorensis, Sow. 



cruenta, Dillw. rubella, Sow. 



dorsata, Gmel. rubicunda, Sow. 



