SEP <5 1896 
ON NAUTILUS AND SOME OTHER ORGANISMS. 145 
Letters from New Guinea on Nautilus and some 
other Organisms. 
By 
Arthur Willey, D.Sc. 
Ratu (New Brirary), German New GUINEA, 
via SINGAPORE ; 
April 5th, 1895. 
Dear Proresson Lankester,—Although I have not seen 
any mature ova of the pearly Nautilus since my last letter to 
you, yet I have made some further observations on the adult, 
which may be of interest. 
1. Ectoparasites.—In my previous note! I accidentally 
omitted to mention the occurrence of numerous Copepod 
parasites in the mantle chamber of the Nautilus. They are 
present in nearly every individual that I have examined, and 
are found attached to the branchix, the internal surface of the 
funnel, and in other regions of the pallial chamber. 
The parasites are a species of the genus Caligus,’? and 
possess the characteristic semilunar suckers on the first pair 
of antenne. ; 
When Nautili are placed in jars the Caligids emerge in 
large numbers from the mantle chamber, and swim about 
actively in the water, usually in close proximity to the sides 
of the vessels, from which they can be removed only with 
some difficulty, owing to the great adhering power of the above- 
mentioned suckers. 
2. Movements.—I send you a photograph of a Nautilus 
in its ordinary swimming attitude,—such a figure, I believe, 
1 “Natural Science,’ May, 1894. 
2 C. nautili, pending a more detailed description. 
VoL. 39, PART 2.—NEW SER. K. 
