208 General Notes. _ [Mareh, 
five years ago Mr. Benj. Gaillou made known the fact that the 
green coloring of the European oyster (O. edulis), is due to the 
fact that it feeds upon a diatom, the Navicula ostrearia Gaillou. 
This has been persistently ignored by the advocates of the copper 
theory, possibly because of the peculiar blue-green of the gill 
. lamellz, etc., of the oyster. The Navicula in question contains a 
blue-green pigment. diffused through its protoplasm. This pig- 
ment is absorbed by the blood of the oyster from the contents. 
of its alimentary canal, and collected by certain secretive cells 
which are limited to the surface of the branchie and the adoral 
face of the labial tentacles. 
Arthropoda—J.S. Kingsley contributes to the Quart. Jour. Mic. 
Science (Oct. 1885), some notes on the embryology of Limulus. 
He regards Limulus as an arachnid, but states that it takes us 
back to a time when the distinctions between the Crustacea and 
Arachnida were far less marked than now. He also describes the 
outlet in the embryo of the brick-red glands. From an article 
in the Quart. Jour. Mic. Science, by Professor A. Sedgwick, it 
appears that there are two species of Peripatus, P. capensis and bal- 
fourt e latter has eighteen pairs of fully developed legs, and is 
of smaller size than the better known species. The male organs 
of Peripatus are a couple of blind tubes, united near their ter- 
mination. It does not appear that any portion can be extruded, 
7 and the spermatophores seem to be deposited upon any part, even 
: on the head, of the female. Yet the uterus of the female, con- 
sisting of two tubes closely applied, is altvays full of embryos. 
Fishes—Dr. J. Beard gives, as the result of a continued study. 
of the branchial sense organs in the Ichthyopsida (Quart. Jour. 
Mic. Sci., Nov. 1885), the conclusion that aż present we are 
acquainted with no invertebrate nervous system which is built upon 
_ the same plan as that of vertebrates. 
O 2 Birds=Dr. H 
- Rhea. The long-billed appearance of R. macrorhyncha is due less 
Ps 
