56 
And of various other foreign authors— 
NON Rhynchonella senticosa , Davidson. 
Rhynchonella senticosa , S. Buckman, 
and not the Rhynchonella senticosa , from the Inferior Oolite, of 
English authors. 
We have found the investigation of this species very difficult, 
it being almost impossible to obtain specimens from the 
localities mentioned by the various authors. We have already 
shown that the English Inferior-Oolite species is different to 
any of the varieties found "on the Continent. Quenstedt, 
having divided his T. senticosa into several varieties, we need 
not consider whether the shell figured by von Buch is the same 
as the Acanthothyris senticosa of d’Orbigny. 
Engel, “ Geognosticher Wegweiser durch Wurtemherg, 
1883,” page 184, gives Rhynchonella senticosa alba , Quenstedt, 
= R. spinulosa , Oppel, from the Weiss Jura « Impressa-thon, 
and Rhynchonella senticosa silicea, Quenstedt, from Weiss 
Jura 6 Korallenkalk. 
Oppel, “ Die Jura formation,” page 608, gives the name 
spinulosa to d’Orbigny’s species; hut Quenstedt proposes the 
name spinulosa for T. spinosa myriacantha , E. Deslongchamps. 
So to avoid confusion we designate the spinose Rhynchonella 
found in Yorkshire as :—- 
Acanthothyris senticosa, var. fileyensis, 
Buckman and Walker. 
Several years ago J. E. Walker found a small specimen of a 
spinose Rhynchonella in the passage beds of the Lower Cal¬ 
careous Grit of Eiley, on the Yorkshire coast. A larger 
specimen was afterwards given to him by Mr. Herries, hut it 
was unfortunately in a broken condition. Lately, several 
specimens have been found by S. Chadwick, F.GkS. They are 
covered with long spines which generally remain in the matrix 
when the fossil is extracted ; more perfect specimens are still 
required before this shell can he fully described. They appear 
to nearly resemble the Acanthothyris senticosa of d’Orbigny. 
The following table will show what species and varieties of 
Acanthothyris occur in the different Oolite strata of England. 
