10 
H. N. MOSELEY, 
rendered transparent and mounted in Canada balsam as 
adhering to the filtering paper. This precipitate when thus 
dried yields the same spectrum as it does when suspended in 
the solution. The spectrum consists of two bands as figured 
(PI. II, fig. 7 d). 
The dried precipitate is insoluble in water, ether, and 
alcohol, but soluble in acidified alcohol, and then gives the 
original acid spectrum (PI. I, fig. 7 c ), and when this solu¬ 
tion is carefully neutralised the original three-handed spec¬ 
trum returns,'but I obtained it only faintly. Though a 
very large quantity of precipitate was removed by ammonia 
from a strong and original alcoholic solution, the solution 
still remained of a vivid colour and gave its three bands. It 
was only after continued addition of ammonia that the whole 
of the colouring matter was precipitated. 
The colouring matter appears to require a proportionately 
increased quantity of ammonia to precipitate it, as the solu¬ 
tion becomes weaker. Both the dried colouring matter 
and the alcoholic solution have maintained their colour and 
properties unimpaired after a lapse of two years. 
Hymenaster .—Several new species of this deep-sea genus 
of Sir C. Wyvillc Thomson were obtained by the Chal¬ 
lenger from deep water. They are of a brilliant scarlet 
colour when fresh, and the colour is rapidly discharged in 
alcohol. The resulting deeply coloured solution yields, how¬ 
ever, no absorption bands, but a spectrum in which, all the 
light except the red is sharply cut oft’. Many other brightly 
coloured star-fish were examined, but with a similar result. 
Hoplacanthinin. —Several specimens of an echinoid of the 
genus Iloplacanthus were obtained by H.M.S. Challenger. 
They arc of a dark madder colour. Observations were 
made on specimens obtained in latitude G°48' N., longi¬ 
tude 122°25' E. from 800 fathoms, October 23rd, 1874. 
The colouring matter is freely soluble in alcohol, yielding a 
madder-coloured solution, which shows in the spectrum two 
not very sharply defined bands (PI. II, fig. 8). The colouring 
matter became precipitated in the alcoholic solution when 
left to stand in about twelve hours. The absorption bands 
could not be obtained from the precipitate. 
Antedoninfrom Ilolothurian- — On Feb. 26th, 1874, in latitude 
62°26', longitude 95°44'E., in the extreme south of the South 
Indian Ocean, a large Ilolothurian, with a gelatinous test, was 
dredged from 1975 fathoms. The holothurian was about ten 
inches long, and three or six broad. The animal was of a 
uniform dark purple colour. The colouring matter present 
appeared to be identical with that obtained from the Antedon 
