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 is so. Apart from 

 this one point, the paper of H^ckel 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 familiaritv with the Plankton fauna. 



W. H. D. 



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 Helicidse. 

 Mr. H. A. Pilsbry proposed (Nautilus, VI, 1892, No. 5, pp. 54-57) 

 a. new classification of N. Z. Helicidoe, the main feature of it being 

 the forming of one genus, Gerontia, of these former genera consti- 

 tuting my family Phenacohelicidce. 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., Ptt/chodon {=Maorianci), 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 nmc- 



