BOUCHARDIA. 577 



sanguinea, Chcm. Spitzbergensis, Davidson. 



Sowerbii, King. transversa, Sow. 



Sub-gen. waltonia, Davidson. 



Shell with the beak truncated by a large incomplete 

 foramen ; deltidia separate. Loop reduced to two simple 

 lamellae furnished with oral processes and attached to a 

 prominent central septum. 



Valenciennii, Davidson. 



Genus MAGAS, Sowerby. 



Shell with a reflected loop attached near the bend to a 

 very prominent central septum. 



Ex. M. Cumingii, Davidson, pi. 131, fig, 1, 1, a. 



In this genus the apophysary system is composed of an 

 elevated longitudinal septum with two pairs of calcareous 

 lamellae; the lower pair, riband-shaped, proceed from their 

 attachment to the crural base by a gentle curve to near the 

 front part of the septum; the second pair extend in the form 

 of two triangular lamellae from either side of the upper edge 

 of the septum. 



Sjwcies of Ma gas. 



crenulata, Soiv. Evansii, Davidson. 



Cumingii, Davidson. 



Genus BOUCHARDIA, Davidson. 



Shell with a minute foramen at the apex of the beak ; 

 deltidium solid. Apophysis anchor-shaped, the central 

 septum being furnished with two short lamellae. 



Ex. B. tulipa, Blainville, pi. 131, fig. 2, 2, a. 



