114 PAPERS, ETC. 
Obs. This species, being from the upper lias of Ilminster, 
is the oldest representative of the genus yet known. It 
may readily be distinguished from the other species by its 
flattened contour, the thinness of its shell, and by the less 
symmetrical arrangement of the internal ridges, these 
being generally seen through the shell, give it a somewhat 
plieated character. Like the ridges in Zel. Davidsonii, 
they are partly obliterated towards the front of the shell. 
Family„—RHYNCHONELLIDE. 
Genus—RHYNCHONELLA.—-Fischer. 
RHYNCHONELLA LOPENSISs.— Moore. —Plate 1, fig. 9—10. 
Shell small—flattened; thickest at the umbo; triangu- 
lar; nearly straight in front, from whence it tapers to the 
beak; deltideum triangular; dorsal valve slightly concave; 
ventral valve proportionately convex. 
Obs. This little species is from a bed of blue oolitie 
marl, occurring in the neighbourhood of Lopen, near 
llminster, where it is very rare. In Mr. Davidson’s 
appendix to his monograph on Brachiopoda, page 30, it is 
named A. triangularis, but that name having been pre- 
viously adopted by Walenberg, it has been altered. 
Family—SPIRIFERIDE. 
Genus—SPIRIFER.-— Sowerby. 
Shells of this family had their introduction at a very 
early geological period. They were numerous in the in- 
tervening periods, up to the lias, in the lower beds of which 
one species, S. Walcottü, is abundant. In the middle lias 
there are two species, S. Munsterü, and S. rostratus. The 
latter species passed into the upper lias, where I have 
found one specimen ofit. In these beds, anew but very 
