166 ARTHUR WILLEY. 
The latter is probably a distinct species from the one I have 
described, although there are many features common to them 
both, particularly the external form and mode of attachment. 
I am a little puzzled to understand what Sluiter says about 
the endostyle, and am inclined to think there must be some 
mistake about it, as there is no trace of a typical endostylar 
epithelium in the section figured by him. I have even 
observed a line or ridge in the ventral surface of the mantle 
corresponding very closely to his Taf. viii, fig. 2, but this possi- 
bly represents the former line of contact between the endo- 
style and the mantle. 
There are naturally a great many more questions to be 
answered in connection with this remarkable Ascidian, but I 
have probably said enough to show that its property of evis- 
ceration is its most distinguishing peculiarity, and thus to 
afford an explanation for an otherwise inexplicable anomaly. 
Yours very truly, 
Artour WILLeEY. 
Raum, GerMAN New GUINEA, 
via SINGAPORE ; 
September 24th, 1895. 
Dear Professor LANKESTER, 
1. Significance of the Siphunele in Nautilus 
pompilius. 
Being desirous of obtaining, if possible, experimental evi- 
dence as to the physiological significance of the siphuncle 
in the pearly Nautilus, I have made several successful attempts 
to cut the siphuncle without otherwise injuring the animal. 
The evidence supplied by the experiment cannot be regarded 
as conclusive, on account of the altered conditions of depth and 
temperature to which the Nautilus is exposed by being brought 
up to the surface, but it may be well to consider what the 
results indicate. 
