213 
AJ»PEND1X III. — NOTES ON SOME YORKSHIRE ECHINOIDS. 
BY E. TALBOT PARIS, F.C.S. 
I. INTRODUCTION. 
The echinoids on which the following notes are based are in 
the collection of Mr. R. S. Herries, F.G.S., and were obtained 
by him from the Estuarine Series on or near the Yorkshire coast. 
The mode of preservation of the specimens renders the identi- 
fication of species — and sometimes of genera — a matter of some 
difficulty, many of the specimens being internal casts, while well- 
preserved portions of the test are extremely rare. 
The specimens examined have, with a single exception, been 
obtained from one of three horizons, namely, the Dogger, IMillepore- 
Bed, or Scarborough Limestone. 
The following table indicates the species which have been 
identified and the horizons at which they occur. 
NAMK OK SPKCIES. 
Acrosalenia lycctti Wright 
Cidaris houchardi Wright 
Polycyphufi deslongdianipsi 
Wright 
Trochotiara depressmn (Agassiz) 
Pygaster ef. semisulcatus 
(Phillips) 
Rhabdocidaris maxima (Munster) 
Stoinechinus interynedius 
(Agassiz) 
1 - 
Middle 
Kstuarines. 
2 ° 
o " 
1.1 
Upper 
Estuarines. 
* 
* 
* 
! 
* 
1 •• 
* 
1 
* 
* 
i 
^ - _ ^_ — „ . „ . — „. — — , ^ ^ ^ . . » 
the Yellow Beds at the Peak, Robin Hood's Bay. 
The association of Acrosalenia lycetti, Polycyphus deslong- 
champsi, and Stomechinus intermedins in the Dogger confirms the 
view that this deposit is of murchisonce hemera. 
The occurrence of Pygaster semisulcatus associated with 
Trochotiara depressum and Cidaris houchardi, in the Millepore- 
Bed, at a considerable distance above the Dogger, is noticeable 
because these species occur in beds of murchisonce date in the 
Cotteswold area. It ma}^ be pointed out, however, that in the 
