186 The American Naturalist, (Febeeany, 
85 are Crustacea; 60 Echinodermata, and 65 Annelids. About 75 
species of fishes have also been found here. Many species, especially 
Crustacea, common in the two previous years, were scarce or absent 
in 1882. This, as well as the great destruction of the tile-fish 
(Lopholatilus) was, in Prof. Verrill’s opinion, probably caused by a 
very severe storm that occurred in this region, which “‘ by agitating the 
bottom water, forced outward the very cold water that, even in sum- 
mer, occupies the great area of shallower sea, in less than 60 fathoms, 
along the coast, and thus caused a sudden lowering of the temperature 
along this narrow warm zone where the tile-fish and the crustacea re- 
ferred to were formerly found.’’—W. N. L. 
The Ectoderm of Spongilla.—According to one group of au- 
thorities the ectoderm of the larval sponge is transformed directly into 
that of the adult, while others claim that during metamorphosis the 
ectodermal larva entirely disappears. To ascertain the real facts in the 
case, Otto Maas contrived apparatus whereby a single embryo of 
spongilla could be kept constantly under observation during all its 
stages until sometime after attachment, and he concludes (Zool. Anz., 
No. 316) that the larval ectoderm is transformed directly into that of 
the adult. At first the cells are columnar ; after becoming attached the 
animals increase rapidly in size, which is accompanied by a flattening 
of the ectoderm, which is now cubical and growing flatter and flatter ; 
the cell boundaries disappear, but always a sharp focusing will reveal 
a double contour. The ectodermal tissue is visible and the layer ap- 
as an extremely thin hyaline membrane. Götte’s sections in 
which no ectoderm was visible are interpreted as artificial products, 
the delicate ectodermal pellicle having been torn away in spots in the 
processes of preparation. 
Copulatory Marks in Spiders.—There are very few instances 
in the animal kingdom of easily recognized marks of copulation, 
The cases of spermatophores protruding from the female genitalia, the 
male copulatory organs adhering in the female of the honey bee, and 
occasional male palpus sticking in the epigyne of spiders, and the 
hardened secretion forming a sort of pocket on the abdomens of cer- 
‘tain butterflies (Parnassia, etc.), are all noticeable from their pecu- 
liarity. Dr. Bertkau finds that in spiders of the genus Argenna a 
similar sign occurs. Immediately after copulation the opening to the 
spermathecz becomes covered with a little white or slightly rosy lid, 
which may be retained for a considerable time, even months. The 
