488 H. Hicks—Pre- Cambrian Voleanos and Glaciers. 
Buvignier’s specimens are from the Coral Rag of St. Michel, 
whereas Brauns quotes it as rare in his Middle Kimmeridge (Ptero- 
ceras schichten), all of which is below the Virgulian, or real Kim- 
meridge Clay of this country. In Yorkshire the principal localities 
have been already indicated. It is local, and only occurs in the 
Coral Rag. The group has never been noted elsewhere in England, 
except in the Upper Corallian at Osmington, where a specimen was 
found by me in 1875, which is of so singular a form as to be almost 
worthy of being ranked as a separate species. 
27.—NerinmZa, sp. Plate XVI. Figs. 9a, 6. 
This peculiar form has externally but little of the aspect of a 
Neringa, and it is only by making a section that we obtain proofs in 
the absence of the aperture. The spiral angle would seem to be 
about 14°, and the whorls are very unequal in height. We perceive 
from the section (Fig. 9b) that the shell was thick and probably um- 
bilicated. The disposition of the interior folds is variable. A 
single specimen found in the Rag Pit at Brompton (my Collection). 
EXPLANATION OF PLATE XVI. 
Figs. 1-3. Group allied to Cerithium limeforme, Remer. 
Fie. la. Cerithium near to limeforme, Rem. Coralline Oolite of Ness. My 
Collection. Natural size. 
» 1b. The same enlarged. 
»»5 1c. The same, whorl considerably enlarged. 
», 2a. Cerithiwm near to grandineum, Buvig. Coral Rag of Ayton. Leckenby 
Collection. Natural size. 
» 2b. The same enlarged. 
>» 2c. The same, whorl considerably enlarged. 
» 84a. Cerithium near to Humbertinum, Buvig. Coral Rag of Brompton. 
Strickland Collection. Natural size. 
», 9383. The same enlarged and restored. 
», 8¢. The same, whorl considerably enlarged. 
» 4a. C. bicinetum,sp.n. Coral Rag of the Howardians. Leckenby Collec- 
tion. Natural size. 
» 46, The same, two whorls enlarged. 
» Oa. C. gradatum,sp.n. Corallian of Yorkshire. York Museum. Nat size. 
»  9b.&c. Enlargements of the same. 
» 6a. C. inornatum, Buvig. Coral Rag, Seamer. Strickland Collection. 
Natural size. 
»» 65. The same, whorl enlarged to show strizx. 
»» 6c. Another specimen (rolled), back and front. 
» (4&0. Nerinea Susiformis, D’Orb. Corallian of Yorkshire. Leckenby 
Collection. Back and front. 
» S8a.&b. N. Moreana, D’Orb. Coral Rag of North Grimston. Strickland 
Collection. Back and front. 
» 9a. &0. Nerina, species or variety. Coral Rag of Brompton. My Collec- 
tion. A fragment; back and front. 
»  10&11 Rolled specimens of WN. fusiformis or Moreana. Coral Rag of 
Brompton. My Collection. 
(Zo be continued in our next Number.) 
II.—Pr-Camprian Voncanos AND GUACIERS. 
By Henry Hicxs, M.D., F.G.S. 
ee subject of the recurrence of phenomena in geological time, 
so prominently brought forward by Prof. Ramsay in his recent 
address as President of the British Association, is one which cannot 
