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POPULAR SCIENCE REVIEW. 
influence of light is so essential to the existence of these animals, that after 
being kept in the dark they soon died. Treated with alcohol, these green 
PI nnaria furnished first a yellow solution, and then a solution of chlorophyll 
of a magnificent green colour. The residue, coagulated and decolorised by 
alcohol, boiled in water and filtered, furnished a clear solution, which, 
treated with iodine, gave a dark blue coloration, indicative of the presence 
of a considerable quantity of starch. — Comptes renclus , December 30, 1878. 
ZOOLOGY. 
A Gigantic Deep-Sea Isopod. — Under the name of Bathynomus giganteus , 
M. Alphonse Milne-Ed wards describes (Comptes rendus, January 6, 1879) an 
Isopod Crustacean of enormous size, dredged by Mr. Alexander Agassiz from 
a depth of 955 fathoms north-east of the bank of Yucatan. This animal is 
nearly ten inches long and four inches broad, and belongs to the great family 
'Cymothoadae. The most interesting point in its construction is to be found 
in its respiratory apparatus. The ordinary Isopods have the abdominal limbs 
modified to form branchiae, but such an arrangement being apparently in- 
sufficient for this comparatively gigantic form, the abdominal feet are con- 
verted into a sort of opercular apparatus beneath which are the true branchiae., 
which resemble little bushes springing from stems, dividing again and again, 
n structure of the respiratory organs which is quite unique among the Isopod 
Crustacea, although one or two forms belonging to the parasitic family 
Bopyridae have branched appendages attached to the sides of the body. The 
position of the eyes is also peculiar. These organs, which are of remarkably 
large size and each composed of about 4,000 square facets, are placed on the 
lower surface of the head, instead of the upper surface as in the allied forms. 
Mouthless Medusae . — M. Mereschkowsky has published some curious and 
interesting observations made by him on two small naked-eyed Medusae of 
the genus Bougainvillea inhabiting the White Sea (Ann. and Mag. Nat. 
Hist., March, 1879). He describes one of these under the name of Bougain- 
villea paradoxa, as a small transparent bell about i inch long, having four 
radiating canals, each with a red ocellus and a tuft of from three to seven 
tentacles at its extremity, while in the centre there is a red manubrium or 
stomachal peduncle with its mouth surrounded by four much-branched 
tentacles. The ova are developed on the surface of the manubrium, to which 
they remain attached for some time. Associated with these normally con- 
structed individuals M. Mereschkowsky found Medusae of precisely the same 
size and form, and showing the four canals, with their ocelli and tufts of 
tentacles, in fact, so far as the characters of the bell were concerned precisely 
identical with the others, but differing from them in the total absence of the 
manubrium. There was no trace of any such organ, and the four radial 
canals met at the summit of the bill without constituting anything that 
could be interpreted as a stomach. Precisely the same anomaly was ob- 
served in the second species, which is a little smaller, and is further distin- 
guished by having the bell more globular in its lower part, but forming 
above a sort of cupola which renders its form very elegant. In both species 
the author was unable to detect anything in the shape of a stomachal cavity, 
