312 Mr. F. Chapman on 
arenaceous types of recent Foraminifera from Mr. F. G. 
Pearcey, and I am indebted to Mr. John Smith, of Kilwinning, 
for allowing me a sight of his specimens of Psammosiphon, 
selected from the Silurian shale-washings, amongst which are 
individuals apparently referable to P. elongatus of Vine; but 
otherwise no figure has been given and only a short descrip- 
tion *, 
In Terquem and Berthelin’s “ Microscopical Study of the 
Clays of the Middle Lias of Essey-les-Nancy ” ¢ some fossils 
are figured and described which are precisely analogous in 
their external forms to certain Rhetic examples of Stacheta. 
Concerning the bathymetrical aspect of the Rheetic Microzoa 
there is not very direct evidence, although what there is points 
in the main towards the shallow-water nature of the deposits. 
The genera which are most commonly represented in these 
beds are Ammodiscus and Haplophragmium, both of which 
are quite unrestricted as to depth, occurring in shallow water 
and down to depths of 8000 fathoms or more. Their small 
size and stunted appearance would lead one to suppose that 
these organisms had lived at great depths, although that 
feature might also be (and, in this case, probably is) occa-~ 
sioned by their having lived under unfavourable conditions, 
such as would result from a change to brackish water. 
The modern representatives of Stacheta are most probably 
the Polytremata and similar adherent forms with acervuline 
ageregates of chamberlets; although the latter are hyaline 
types, yet one series is possibly only a modification of the other. 
This relationship would indicate shallow-water conditions, 
since Polytrema is characteristic of such deposits. 
The occurrence of bone- and teeth-fragments in nearly all 
of the various beds examined also points to the shallow-water 
origin of these deposits. 
The presence of crystal-impressions in the tests of these 
fossils (presuming they were once occupied by a zeolite) is 
somewhat opposed to the idea of its being a shallow-water 
fauna, since crystals of phillipsite occur in the deeper deposits 
of the ocean. 
I take this opportunity of expressing my best thanks for 
invaluable aid in many particulars to Professor ‘IT. Rupert 
Jones, F.R.S., to Protessor J. W. Judd, C.B., F.R.S., to 
Mr. Fortescue W. Millett, F.R.M.S., and to Mr. C. Davies 
Sherborn, F'.Z.8. 
* Quart. Journ. Geol, Soc. vol. xxxviii. (1882) p. 
+ Mém. Soc. Géol. Fiance, sér, 2, vol. x. (187 
pl. ix. figs. 1 a-e, p. 105, figs. 3 aS. 
