ZURCHERIA. 
293 
Lastly, Humphriesianum-zone — the strata wliicli equal the " Coronaten- 
Schichten " of Quenstedt. 
Literature. — Very few works deal with the SonnininaB to any great extent. 
The most important, perhaps, is "Waagen's ' Zone des Amm. Soiverhyi,'^ wherein a 
fine series of Ammonites is figured, and the Sowerbyi-zone is treated exhaustively. 
There is an interesting little pamphlet by Douville ^ with the same title, containing 
figures of several new species ; and, lastly, Quenstedt's grand work, ' Schwabischen 
Ammoniten,' vol. ii, illustrates a wonderful variety of forms of the genus 
So7ininia. 
It is remarkable, however, that in none of these works are any of the species 
of Sonninia peculiar to the Goncavitm-zone figured. The Sonnininse of the 
Sherborne Quarry — the species of the Sowerbyi-zone — are very fully illustrated, 
especially by Quenstedt, but the numerous forms which occur in the Goneavum- 
zone appear to be wholly unknown upon the Continent. 
i^ami7?/— AMALTHEIDiE, Hyatt. 
Sub-family — Sonninin^, BucJcman. 
Oenus — ZuRCHERiA,^ Douville. 
{Type — ZuRCHEEiA TJbaldi, Dou.ville.) 
1885. ZuECHEEiA, Douville. Zone a Am. Sowerhyi ; Bull. Soc. Geol. France, 
3e serie, t. xiii, p. 37. 
Discoidal, compressed, uncarinate. Whorls ornamented with more or less 
direct costae with a spine at each end, or with a spine at the outer end only, or 
Sauzei-zone. 4. The Ieon-shot Bed. — Hard, brown iron-shot Oolite, Sonninia, Stephana- Ft. In. 
ceras, JPleurototnaria elotiffata . . . . .10 
5. Rubbly stone ....... 4 
6. Greyish limestone ...... 7 
D<h>-c'/ a 7. White Bed below the Ieon-shot. — Greyish-white stone with numerous 
^ ferruginous grains, Witchellia irequent . . . .6 
8. Irregular marl ....... 1 
Concavum- 9. Nodular Bed. — Marl with irregularly bedded limestone nodules, Lioceras 
zone concavum, Hyperlioceras, &c. . . . . .60 
The fauna of the Sowerbyi-zoxm as obtained from Sherborne is almost entirely absent. The 
genus Witchellia appears to correlate No. 7 with the Sausei-zone of Oborne, while No. 4 may be the 
representation of a transition period between the Sauzei- and Humphriesianum- zones of Oborne. 
1 ' Geogn. Pal. Beitriige,' Bd. i. Heft 3, 1867. 
2 ' Bull. Soc. Geol. France,' 3e serie, t. xiii, 1885. 
^ M. Zurcher, engineer, Toulon. 
