THE NAUTILUS. 35 
I found this shell in a small slough near Edwards Creek, in Green 
Township, adhering to flat limestone rocks. I have never found it 
in any other locality. It is probably very rare here. 
GENERAL NOTES. 
On Hevix (Arronta) KreLvett Fss.—Twenty years ago, Dr. 
J. G. Cooper, writing of the west coast helices, mentioned the find- 
ing of Arionta Kellettii F'bs., upon the seaward side of Point Loma, 
at the entrance of San Diego bay. He remarked upon the great 
number of dead shells and the scarcity of the living, from which it 
was inferred that they were dying out. The same state of affairs 
exists to day. The steep hillside is thickly strewed with dead shells 
of the form of Arionta Kellettii, now generally known as A. Stearn- 
siana, while living specimens are hard to find. The dead shells are 
in all stages, from fresh and bright to chalky.and broken, showing 
that a comparatively small number of individuals are living at one 
time, yet enough survive to keep the race intact.—E. W. ROPER. 
PUBLICATIONS RECEIVED. 
CONTRIBUTIONS FOR A SYSTEMATIC KNOWLEDGE OF THE AQUATIC 
SHELLS OF TASMANIA, by W. F. Petterd. In this valuable paper 
Mr. Petterd has revised the fresh-water shells of Tasmania, giving 
especial attention to the minute Paludinoid forms, which in Tasmania 
as everywhere have been very imperfectly understood. Most of 
them belong to the genus Potamopyrgus of Stimpson, a group in- 
cluding also all of the New Zealand non-marine Rissoids. The new 
subgenus Beddomeia (name preoccupied by Nevill, Handl. Moll. Ind. 
Mus. i, p. 127) is proposed for Amnicola launcestonensis Johnson, and 
other species, and Brazieria for the Ampullaria tasmanica Tenison- 
Woods. A number of new species are described and figured as well 
as the radule of various genera. The importance of work of this 
sort can hardly be oyer-estimated at the present stage of Malacology. 
—H. A. P. 
ON CERTAIN PARASITES, COMMENSALS AND DOMICILIARES IN THE 
PEARL oOysTER, by R. E. C. Stearns. (Smithsonian Report, 1886, 
pt. 1, p.339.) The author of this paper discusses in characteristically 
graceful style the interactions between parasites, domiciliares and 
