84 O. A. MAC MUNN. 
probably to its being enclosed within the substance of the tunic. 
Nothing else worthy of notice was found in this Ascidian. 
In Ascidia virginea a brilliant red portion within the 
tunic absorbed the green strongly, giving a kind of double 
absorption band there, and also strongly absorbed the violet 
end. No other part of the animal showed a band. The red 
colouring matter went only to a very slight extent into alcohol ; 
this solution gave a faint band in the blue end of green, and its 
yellow residue became faintly greenish with nitric acid, reddish 
and violet with sulphuric acid, and was unchanged by iodine in 
iodide of potassium. When treated with caustic potash the 
red pigmentary parts in the animal lost their red colour, 
becoming yellowish. On the whole probably a lipochrome was 
present, but owing to its situation it could not be extracted in 
the usual way. 
In the Cynthiew and Didemnide Krukenberg! found 
mostly lipochromes—(chlorophans and rhodophans). In some, 
e.g. Ascidia fumigata and A. mentula, a yellow uranidine 
occurs which causes the lymph as well as the inner organs by 
contact with the air to become dark brown; and the black 
pigment in the mantle of Ascidia fumigata may be, accord- 
ing to the same observer, an ‘‘ Umwandlungs product ” of this. 
C@LENTERATES. 
I have shown in my paper “On the Chromatology of 
Sponges’? that chlorophyll is present in a great number of 
sea-water sponges, probably in seventeen at least. Kruken- 
berg? has lately found a chlorophylloid pigment (hepato- 
chromes = enterochlorophyll) in several corals from the Red 
Sea, besides what he calls “anthea green,” red and purple 
“floridines,” a yellow “uranidine,” chlorophans and rhodo- 
phan-like lipochromes, and a red lipochromoid. In fact, as 
our knowledge of the colouring matters of animals extends we 
see that the number of chlorophyll-containing animals is 
1 “ Grundzuge,” loc. cit., 8. 134. 
2 «Journ. Physiol.,’ vol. ix, No. 1. 
5 *Vergl. physiol. Studien,’ ii Reihe, 4 Abth., S. 172—186, 
