Echinoderm-Fauna of Ceylon. 219 
they will be found to teem with many new forms, it seems 
to be of interest and importance to give a brief statement 
as to what may be found by an active worker who will devote 
a short time to the occupation of collecting. 
Dr. Ondaatje, Colonial Surgeon in Ceylon, has lately ar- 
rived in England, and has presented the Trustees of the 
British Museum with, énter alia, a collection of Echinoderms, 
of which the following is a list. 
ECHINOIDEA. 
1. Diadema setosum. 
Well as the spines of this species are known to vary, I do 
not know whether a specimen with a number of its spines 
perfectly white, while others are more or less dark brown, has 
ever been put on record. 
2. Echinometra lucunter. 
It is well to have evidence that this widely distributed and 
very variable form is found off Ceylon. 
3. Salmacis bicolor. 
Since the time when I communicated to the Zoological 
Society some observations on the Temnopleuride*, and when 
the only specimens in the British Museum from a definite 
locality were those collected by H.M.S. ‘ Challenger’ at 
Zamboanga, examples have been received from Port Molle (E. 
Australia) and from Mauritius. ‘This species, then, is another 
of those which may be expected to be found throughout the 
whole area of the Indian Ocean. 
Some years ago Dr. von Martens described a species which 
he called Salmacis conica; but this, in the opinion of Mr. 
Alexander Agassiz, is only a form of S. sulcata. The propor- 
tion of height to diameter in von Martens’s species was 76°83 per 
cent. ; the example now in our hands presents a proportion of 
84 per cent.; and we have therefore the interesting case of 
the same kind of variation in shape presenting itself in two 
closely allied species in which, as a more ordinary rule, the 
longitudinal is never more than 65 per cent. of the transverse 
axis. 
4, Hchinoneus cyclostomus. 
5. Lchinodiscus biforis. 
I adopt, provisionally, the specific name used by Agassiz in 
* P.Z.S. 1880, p, 422. 
as 
