THE NAUTILUS. 89 
ber of rib-like irregular ridges’’. P. pennsylvanicus Pils. (Proe. 
Acad. Nat. Sci. Phil., p. 22, 1894) is described as being 
‘¢ smaller and less distinctly marked than P. carolinensis’’ and 
‘‘having the jaw strongly ribbed’’, a description which could 
not be applied to P. rushi. 
CLIMATIC CONDITIONS 48 INDICATED BY LAND SHELLS OK THE 
ISLAND OF OAHU. 
BY J. J. GOUVEIA.' 
Since the early part of 1913 the writer and his brother A, 
Gouveia have been engaged in making a collection of Hawaiian 
land shells, both ground and tree. We have accnmulated spec- 
imens of shells from nearly all valleys and ridges on the island 
of Oahu. We have complete data as to the exact locality and 
habits, so it can be seen that the writer has a good prooi, from 
his series, of Gulick’s theories of segregation or isolation. This 
idea has been written and followed out by many other collectors 
and students until it is well known in the scientific world. One 
of the best examples of this is seen in Dr. Cooke’s paper on 
Achatinella multizona. 
DisTRIBUTION OF Achatinella cestus FROM MANOA-PALOLO RingE 
to WatLuPe-Nivu Ripee.—Achatinella cestus (Newcomb) is found 
mostly on lehua or one of its related plants having a rather 
large dark green and glossy leaf, on Jeie, Opiko and Lantana, 
and nearly always under leaves, with the exception of the 
Wailupe-Niu locality where they are found mostly on Lantana 
stems. They are nearly always found sealed. The only time 
they are found extended is when they are disturbed by wind or 
rain or accidentally brushed off, so they must be nocturnal as 
Dr. Cooke surmises (1). 
They are very variable in color from white to very dark 
brown. They are lighter on the western part of the range and 
become darker towards the eastern part. The greater part of 
these shells have a white border band (2). 
1 Contribution from the Gulick Natural History Club. 
