150 CRETACEOUS GASTROPODA 
to the other known species, which have been quoted. Excepting the Tudicla per- 
lata, Cour. (prob. Z. trochiformis, Tuom.), Morea cancellaria, Conr., Whitneya ficus, 
Gabb we may say, that there is not a single species the generic determination of 
which was unquestionable ; the largest number of them being based upon imper- 
fect cast specimens. The most probable are those described by Binkhorst from the 
Meestricht Chalk and, so far as the sub-family is concerned, they cannot be very 
much doubted. But supposing the most unfavorable case, that only little more than 
one-half of the species, which we have quoted, are found correct, we have still a 
fair number of cretaceous Kapanine, amounting to 16 species, a number to which 
the tertiary species scarcely attain, showing thus the importance of the study of the 
Purpuride for the cretaceous deposits. It is remarkable, that scarcely any repre- 
sentatives of this sub-family are known from the cretaceous deposits of Southern 
Hurope, while the species in the deposits of Northern Europe, as in England, Ger- 
many, Bohemia and Galicia, are by no means rare, even as regards individuals. The 
difference seems actually to exist, as it cannot be entirely due to a better and more 
extensive knowledge of the fossils of the northern cretaceous deposits. I never met 
with a species of this sub-family in the deposits of the Alpine Gosau formation, 
although I had repeatedly occasion to look over large collections from these beds, 
and to a great extent examined the same also in situ. 
XXXVII. TUDICLA, Bolten, 1798. 
Char. Testa fusiformi, spira brevi; ultimo anfractu ventricoso, antice canali 
prolongato ; apertura ovali sew rotundata, postice subcanaliculata ; labio calloso, 
postice plicose-dentato, antice applanato, intus acute angulato atque plicam formante ; 
columella late excavata. 
The posterior tooth on the inner lip and the anterior fold of the same may be 
considered as the principal distinction between Tudicla and Rapa; the length of 
the canal is probably also characteristic, and is well developed in Rapa only in 
younger specimens. The papillary apex must be excluded from the character, as 
it does not exist even in such typical forms as Tudicla rustica, Bast., which several 
conchologists up to the present time consider as identical with 7. spirilla. 
I adopt here Bolten’s name, not because I would favor any ill-founded claim 
of priority against Pyrella or Spirilla, but because the name Tudicla is not likely 
to be so easily mistaken, and is in reality better known than any of the former, 
specially through Adams’ and Chenu’s conchological works, and because it has 
already become familiar in palzeontological literature as well. It is quite the same 
in the case of this genus as with Meptunea of the rusrv# and many others. 
Several conchologists may think it a novelty to find the genus classed here. 
Ido not know more about the living shells than is stated in known conchological 
publications, and I have been led to the present placing of the genus in this sub- 
family merely by the very great resemblance of the form of the shell to that of 
