210 CRETACEOUS GASTROPODA 
a higher degree. With the exception of some species of ZLoxonema (sub-family 
cHEuNiTzuN& of Hurmurpx), I do not know a single shell, which would agree in all 
its characteristics with the original Proto Maraschini of Defrance; and should it be 
really different from the last named genus, (for it is perfectly impossible to decide 
this either from the existing figure or description), it must receive a new generic 
denomination, as that of Proto had been already, before Defrance, applied by several 
authors in a different sense. This genus must then be placed in the cxzuyirziya, 
or, if its relations to Chilocyclus can be better established, in the Scazrpm. 
Blainville, following Defrance’s later researches on his Proto, placed the Twrr. 
cathedralis in the same genus, and as this species was well known to many concho- 
logists, the consequence has been, that the characters of Proto have been defined 
from this second and not from the original species, for which the name was at first 
proposed. Hence all the subsequent controversies between different authors. 
The shell of Zurr. cathedralis is remarkably strong and solid, as compared with 
most other Turritelle ; the outer lip is thin, with a broad insinuation in the middle, 
and a second narrower but deeper insinuation is found anteriorly, producing on the 
basis of the last whorl the formation of an elevated ridge, which consists of thin, 
single lamellze according to the progressive growth of the shell. In some speci- 
mens at least, as seen, for instance, in Sowerby’s figure, in the Quart. Journ. Geol. 
Soc., Lond., IIT, pl. 20, fig. 26, the anterior portion of the aperture was distinctly 
produced into a kind of short canal, which is very rarely developed to that 
extent in the cretaceous species of Glauconia. In these the anterior channel 
is moreover replaced by a simple insinuation, but in every other respect they are 
quite similarly formed. 
Comparing thus the Turr. cathedralis with the genus Glauconia, it is really 
difficult to point out any characteristic distinctions, save perhaps the great length 
of the spire of the former. I may add that the species does not, at least in the 
Vienna basin, occur in truly marine beds, but rather in brackish deposits associated 
with poraurprinm, such as Cerith. margaritaceum, C. plicatum and others. It is 
therefore very probable, that Z. cathedralis ought to be regarded as the tertiary’ 
representative of the cretaceous Glauconia. 
Pictet and Campiche (Pal. Suisse, 38me. Ser., p. 311, ete.,) reserve the species of 
Glauconia under the name of Twurritella, and propose three sections in that 
genus, two for the genus Glauconia, and one in which they place all the species 
commonly known as Turritella. For the two first they take as a ground of distine- 
tion the presence or absence of an umbilicus. We do not in the least intend to 
deny the importance of those characters in many cases, but we cannot help doubt- 
ing their value in the present one. For we have repeatedly observed, (vide Sitzb. 
Akad., Wien, Revision der Gosau-Gastropoden, pp. 11-15), that the columella is in 
one and the same species sometimes solid, and at other times hollowed out. It is 
by no means rare to find young shells provided with a large open umbilicus, 
while fully grown ones have no trace of it. Such is really very often the case with 
Glauconia, and full grown shells have, in consequence of the great thickness of 
the inner lip, the columella apparently quite solid. For these and other considerable 
