THE NAUTILUS. 87 
Agassiz and Tanner are superior by reason of their better apparatus 
to any heretofore made, and they seem to show that with the excep- 
tion of a superficial zone of a few hundred fathoms and a thin zone 
immediately over the bottom, the animal kingdom is represented in 
the intervening region by the dead bodies of sinking animals only, 
and has no peculiar fauna of its own and but little life. There is 
no obvious reason why this must be so, but the most carefully 
checked observations yet made indicate that it isso. Apart from 
this one point, the paper of Heckel gives a most interesting, accu- 
rate and vivid idea of the pelagic life of the sea, and one which 
every one may read with profit. The vast experience in surface and 
coast collecting which the Jena Professor has had, enables him to 
speak from experience in this direction, and the material obtained 
by others, on the Challenger and elsewhere, which he has worked 
up, has given him great familiarity with the Plankton fauna. 
Ws Et? 
CONTRIBUTIONS TOWARD A REVISION OF THE TASMANIAN LAND 
MOLLUSCA. 
BY H. SUTER. 
Since I wrote the “ Preliminary Notes on Tasmanian Land Shells,” 
I have sacrificed many more specimens of my collection for the 
study of the dentition, and, as I have just finished the work, I wish 
to give here the result of my investigations. 
Before giving the results of my study, it will be necessary to say 
a few words on the classification of the New Zealand Helicide. 
Mr. H. A. Pilsbry proposed (NautiLus, VI, 1892, No. 5, pp. 54-57) 
a new classification of N. Z. Helicide, the main feature of it being 
the furming of one genus, Gerontia, of these former genera consti- 
tuting my family Phenacohelicide. Later on he published (Proc. 
Acad. Nat. Sci. Philada., 1892, pp. 387, etc.) a “ Preliminary Out- 
line of a New Classification of the Helices,’ in which he included 
under the one genus Endodonta, the following groups: Endodonta 
s. str., Ptychodon (=Maoriana), Charopa, and his genus Gerontia. 
I can not agree with this latter classification, as the author was 
under the impression that Endodonta, Charopa, etc., possess a muc- 
