GEOLOGICAL EANGE 263 



in elucidating the Liassic foraminiferal fauna. An 

 important find was made by Haeusler some years ago 

 in the sandy marls (Oxfordian) of the Canton Aargau, 

 in Switzerland, where a remarkable series of Forami- 

 nifera was discovered from the zones of Ammonites 

 transversarinH and A. hiiiKtuiinatus. This fauna 

 comprised many nodosarian forms, but the larger 

 part consisted of arenaceous genera, the existing 

 forms of which usually indicate deep-water conditions. 

 To mention some of the arenaceous genera met with, 

 we may quote Psammosplicera, Astrorhiza^Illiahdam- 

 7iiina, Marsipella, Hyperammina, Lituola, Beojjhax, 

 Haplopliragmium, Haplostiche, Placopsilma, Tro- 

 chammina, Ammodiscus, Hormosina, Wehhina^ 

 Tliurammma, Textidaria, Bigenerina, and Valviilina. 



In the Oxford Clay of Weymouth, in England, the 

 porcellanous type Nuhecidaria is frequently found 

 covering the exterior of large shells, such as GryplicBa, 

 with their ramifying tests. 



The Kimeridge Clay is also prolific in Foramini- 

 fera at some localities, the prevailing genera being 

 Cristellaria and Pulvinidina. 



The Tithonian beds (Portlandian) of the Continent 

 have yielded many interesting genera, notabl}^ 

 Involutina, Haplopliragmiuni, Valvulina, Nodosaria, 

 Frond icidar id, and Cristellaria. The facies appears 

 to be a transitional fauna between the older and the 

 newer Mesozoic strata. 



The Neocomian and Aptian formations, both in 

 England and in Germany, contain a comparatively 

 sparse foraminiferal fauna, owing to the lithological 



