98 
EUOMPHALUS catillus. 
TAB. XLV. — Fig. 3 and 4. 
Helix catillus*. Martin Petr if. Derb. 
... — — — — 
Spec. Char. One prominent ridge upon each side: 
Volutions almost wholly exposed : Aperture a 
triangle, two sides of which are much longer 
than the third : umbilicate side an hollow cone. 
it rob ably as thin a shell as the last; its proportions are 
about the same ; the principal difference lies in the prominent 
ridge on the under side, which gives the aperture a triangular 
form. 
It is now ten or twelve years since I received specimens 
of this shell from Mr. Martin, the late intelligent Author of 
u Petrificata Derbiensia;” it is found at Tideswell, Winster, 
Buxton, &c. in Derbyshire. Fie observes that the spe- 
cimens are very much compressed in the shale which inter- 
poses' between the Limestone and Gritstone strata. Mr. 
Parkinson has figured a similar, but perhaps plainer species 
of this Genus as approaching the Delphinula, and rather 
unfortunately quotes Brander’s Fossiiia Hantoniensia, Tab. 
10. F. 7 and 8 (which is a Solarium of Lam.) as an 
example. Walcot has also a specimen, probably of this 
Genus, as a Bath Petrifaction, Fig. 56, Both are probably 
different species. I have not yet seen such from Bath. 
J udging from a fragment I received from my kind friends 
Mr. Winsor and Mr. Ducket, in Nov. 1810, I should guess 
that a very similar species is found at Scalaber near Settle in 
Yorkshire, which is four or five inches in diameter. 
* Catillus signifying a little dish or porringer, which it may be consi- 
dered as resembling when placed with the upper side downwards. The 
next species might, however, with as much propriety, be designated by the 
specific name Catinus, a large porringer. 
