Reviews—M. Cossman—Oligocene Fauna of Etampes. 425 
species from Htampes, hitherto classed with Trochus, are now to be 
ealled Hlenchus. Trochus bicarinatus, Lamk., has been expunged 
from the catalogue on the ground that only one example of the 
species is known, and that is probably a deformation of Hlenchus 
subincrassatus. The genera Gibbula and Turbo are’ represented by 
one species each, and Collonia by two. 
Neritopsis Lorioli, Cossm. and Lamb. is very properly transferred 
to Nerita; and Neritina propinqua, Cossm. and Lamb. is merged into 
N. Duchasteli, Desh., of which it is only the adult form. There are 
five species of Odontostomia; one, O. Lamberti, being new. Passing 
to the genus Raulinia, which both Fischer and Tryon have classed 
with the Littorinide, the author shows that it more properly finds 
a place in the Pyramidellide, close to Odontostomia, a conclusion 
arrived at from the study of the embryo. Two species of Raulinia 
are found near Ktampes. Amongst the Pyramidellide, also, a new 
genus Belonidium, is proposed, of which the type is Aciculina 
gracilis, Desh. 
The well known Ampullina crassatina, Lamk., is correctly referred 
to the genus Megatylotus, characterized, amongst other things, by an 
immense, broad, columellar callosity, sharply defined. The author 
seizes the opportunity to give the geographical distribution of this 
species. Truncatella Bezanconi is the name given to a new species 
discovered at Jeurre; we believe it is the sole representative of the 
genus in the Oligocene beds, although two species have been 
described from the Parisian Hocene. 
Dealing next with Hydrobia we take objection to the figure and 
description, in a work devoted to Paris basin fossils, of a new 
Spanish species, H. Rodillensis, which is entirely out of place, even 
though it is incidentally alluded to in connection with H. Dubmissoni, 
Bouillet, a common form at Etampes. Littorina obtusangula, Sandb., 
a species occurring in the Mayence basin, has been added to the 
fauna under notice by the discovery of an unique specimen. Four 
species of Lacuna are found; one of them, L. stilpna, which is 
figured, was formerly referred in part to L. striatula, von Koen., now 
said not to occur in the Ktampes area. 
The fact that Mr. R. B. Newton has shown that Bayania semi- 
decussata, Lamk., is synonymous with the earlier B. corrugata, 
Lamk., seems to have escaped M. Cossmann’s attention. 
We cannot conclude our observations on this very valuable con- 
tribution to our knowledge of the Paris basin Oligocene mollusca, 
without expressing a regret that its learned author did not include 
in his revision the mollusca from the same horizon of other parts of 
the basin; they are not numerous and would have entailed but very 
little additional labour. The catalogue would then have been more 
comparable with his Eocene work. We may point out also that 
the title “marine” is not strictly correct as applied to the paper 
under review, seeing that several extra marine forms are described 
in it. It is a pity they were not all included, and the title suitably 
altered ; but we are, perhaps, expecting too much. The work, so 
far as it goes, is most excellent. Gis Es 
