Rhetic Foraminifera from Somerset. 311 
The affinity which these Rheetic Foraminifera bear towards 
the younger (Jurassic) strata is also marked, since many 
characteristic arenaceous forms present in the Rhetic clays 
have their analogues in the faune of the Swiss Jurassic 
(Argovian) beds of the zones of Ammonites transversarius 
and A. bimammatus (=Corallian) described by Dr. Rudolf 
Heeusler *, 
As regards the foraminiferal facies of the Lias, a complete 
comparison cannot be made with the Rhetic fauna, for the 
former group of beds have yielded a large preponderance of 
the pertorate Foraminifera, whilst the arenaceous types, which 
are so well represented in the Rheetic beds of Wedmore, are 
poorly represented in the Lias. In a sample of the Upper 
Lias (Leda-ovum beds) of Northampton, kindly given me by 
Mr. J. Harrison, of the Royal College of Science, I have, 
however, found examples of Ammodiscus, such as A. anceps, 
A, centrifugus, and A. Robertsoni, which brings the range of 
these forms from the Carboniferous up to the Lias strata. 
The examination of the Rhetic clays of Wedmore has 
resulted in the discovery of certain species of Stacheia which 
are comparable with the hitherto obscure and imperfectly 
known fossils described by Mr. G. R. Vine in 1882 t, and 
for which he proposed the generic name of Psammostphon, 
placing it in the class Vermes, and regarding the fossils as 
being related to the tubicolate Polychaeta. ‘Two species of 
Psammosiphon were described by Vine—P. amplexus and 
P. elongatus. The original specimens were obtained from 
Silurian strata of Wenlock age—the Coalbrookdale beds and 
the Tickwood beds. During the examination of similar 
fossils from the Rheetic such evidence was obtained as to 
fully establish them as true Rhizopods, and belonging to 
the well-known Carboniferous genus Stachefa. I have 
since found similar fossils in some numbers in the Silurian 
strata (Wenlockian) of the island of Gothland; for a sample 
of the clay I am indebted to Mr. F. A. Bather, M.A., F.G.S. 
For the opportunity of examining in thin sections some of the 
original specimens of Psammosiphon amplexus in the Vine 
collection at the Royal College of Science I wish to express 
my sincere thanks to Professor Judd, C.B., F.R.S. 
In the elucidation of these somewhat problematic fossils 
much assistance has been afforded me by the loan of some rare 
* “ Monographie der Foraminiferen-Fauna der Schweizerischen Tians- 
versarius-Zone,”’ Abhandl. der Schweiz. paleontogr. Gesellsch. vol. xvii. 
(1890). 
+ Quart. Journ, Geol. Soc. vol. xxxviii, (1882) pp. 390-392, pl. xv. 
fic, &. 
