646 Brett—On the Echinoderm Fauna of the Island of Ceylon. 
B.—ECHINOZOA. 
i AS PE OTD EAs 
6. LiIncKIA LEVIGATA. 
Asterias levigata. Gmelin, Syst. Nat., p. 3164. 
Ophidiaster miliaris. Miiller and Troschel, System der Asteriden, p. 30 ; 
Perrier, Rév. Stellér., p. 1387. 
Linckia levigata. Liitken, Videnskab. Meddel, p. 47; Bell, Rep. Voy. Alert, 
p. 124; Proc. Zool. Soc., 1887, p. 139. 
This species is often distinguished by its blue colouration, and, contrary to 
what ordinarily happens with the colouring matter of starfishes, this blue colour is 
often well preserved in dried specimens; it would be interesting to make a 
chemical and spectroscopic investigation of this body. The museum examples 
from Ceylon were obtained by Mr. E. W. H. Holdsworth. 
7. LiNcxia, sp. 
Linckia, sp. Walter, Jenaische Zeitschrift, xviil., p. 366. 
Dr. Walter thinks this may be the same as the succeeding species. He was kind 
enough to promise to use his best efforts with the authorities of the Jena Museum, 
in order that I might be allowed to examine one of the specimens myself; but the 
starfish has never reached me. 
8. SCYTASTER NOVAE-CALEDONIAE. 
Scytaster nove-caledonie. Perrier, Réy. Stellér., p. 162. 
In my earlier essay I used this species as the text for insisting that an injury 
to an arm might be accidental—that is, that it might be due to external forces 
depending on the will of another animal. Put im less general terms, one means 
here that a starfish may lose an arm by having it bitten off. The differences 
‘between a loss by external means and the so-called voluntary process are obvious 
enough. In the latter case the arm is marked by a longitudinal constriction, 
which, becoming deeper and deeper, finally separates the distal from the proximal 
or basal portion. In a specimen of Scytaster now before me, two of the arms are 
cut across obliquely, and the freshly-grown portion of one of them has its long axis 
a little oblique to the original long axis of the arm; these characters combined 
