ON COLOURING MATTERS. OF VARIOUS ANIMALS. 5 
a mottled yellow and brown colour. The pink colouring 
matter in the fresh condition yielded a single well-marked 
absorption band (PI. 1, fig. 4). The colouring matter when 
dried retained its spectrum. It was insoluble in absolute 
alcohol. The filaments emitted from the pores in the body- 
wall of these Actinia: were of a light red colour. This colour¬ 
ing matter gave two absorption bands in the green which 
were unfortunately not mapped. 
Ccenopsammia .—A Eupsammid coral (Cocnopsammia sp.) 
is extremely abundant about tide mark in sheltered bays at 
St. Vincent, Cape Verdes, attached to the rock in masses, 
and very conspicuous from its red colour. Some specimens 
are yellow, and some, half red, half yellow, were met with. 
Also a red specimen with a yellow bud. The red colouring 
of the corallum gives an absorption band, the position of 
which was not determined. 
Echinoderms. 
Purple Pentacrinin .—Many specimens of several species 
of Pentacrinus were obtained in various parts of the world 
by IT.M.S. Challenger. Several of these species are new, 
and will be described in due course by Professor Sir C. 
"Wyville Thomson. 
Spectroscopic observations were made on specimens ob¬ 
tained on five different occasions and localities, viz. 
Off the Kermadec Islands, July 14th, 1874, from 630 and 
650 fathoms. 
Off the Ke Islands, September 26th,1874, from 126 fathoms. 
Off Cebu, Philippines, January 26th, 1875, from 100 
fathoms, with Euplectella aspergillum. 
Between Panglao and Siquijor Islands,Philippines, January 
25tli, 1875, from 375 fathoms. 
Off the Meangis Islands, February 10th, 1875, from 500 
fathoms. 
The majority of the specimens were found to yield a 
colouring matter which is extremely well defined by char¬ 
acteristic absorption spectra, and which may be termed Pen¬ 
tacrinin, having as yet, been observed only in the genus 
Pentacrinus. In the fresh condition the colouring matter is 
freely soluble in slightly acidified alcohol, and gives a solu¬ 
tion which is of an intense pink colour when viewed by 
transmitted light. The solution when moderately intense 
gives a spectrum consisting of three bands (PI. 1, fig. 5 a). 
One of these, intensely black with sharply defined margins, 
covers the D line extending for a very short distance 
beyond the more refrangible side of that line, and for a 
greater distance on its other side towards the red, as was 
