64 
short ones ; those costae which are near the posterior side are 
suddenly bent before they pass over it ; over the anterior 
side are scattered some small irregular thread-like lines, 
and near the edge a few obscure tubercles. The beaks 
are rather prominent. 
This was sent me several years ago by the Rev. H. 
Steinhauer, from the inferior Oolite of Little Sodbury. 
None of my specimens have the anterior side complete : 
the dotted outline is from a specimen which belonged to 
the Rev. Mr. Townsend, in recollection of whose merits 
I take a pleasure in mentioning his name. It is from the 
double series of costae near the front that the shell is 
named. 
TRXGONXA pennata. 
TAB. CCXXXVXL —Fig. 6. 
Spec. Char. Oblong, transverse, with concentric 
costae ; along the middle of the anterior side is 
a ridge from which many tuberculated ridges 
diverge each way. 
The concentric costae are striated upon their fronts; at 
one end they join the ridges upon the anterior side which 
diverge from a central line like a feather. 
I have only seen one, and that a very imperfect cast of 
this shell, but as there are characters enough to distin- 
guish it by, I thought it might be a useful addition to this 
plate. It occurs with casts of other Trigoniae and Oyster 
shells, in a mass of coarse Quartzose sand, mixed with 
green sand, cemented by Carbonate of Lime, which was 
sent me from Teignmouth, by Thomas Hare, Esq, 
