202 
SPOLIA ZEYLANICA. 
in the liver, mantle, and gills ; and a more advanced Tetrarhyn- 
chus is found in the file fishes, Balistes mitis and B. stellatus , 
which feed upon the oysters. The sexually mature Cestode has not 
yet been found, but we may expect it to occur either in one of the 
large Elasmobranchs (such as Trygon uarnak) which abound on 
the pearl b inks, or possibly in one of the smaller cetaceans, which 
may also feed upon such fishes as Balistes. 
7. On a Phosphorescence Phenomenon in the Indian Ocean . 
(By Professor W. A. Herdman. D.Sc., F.R.S.*)—Professor 
Herdman described how during his recent expedition to Ceylon, 
as they lay at anchor in the Gulf of Mannar on 13th March, 
1902, about 9 P.M., the sea was seen to be dotted with bright 
phosphorescent lights of considerable size, singly placed at some 
distance apart. These for over an hour continued to glow with a 
pulsating appearance in harmony , all shining brightly at the same 
moment, and then all flickering out together, to re-appear simul¬ 
taneously a few seconds later. On going out at once with a net 
a sample of the plankton was obtained, but it was not certain that 
any of the pulsating forms had been caught. The gathering 
contained Sagittate ry many), Appendicularia, Copepoda, several 
common species, and Sapphirina sinuicauda , Pontella fera , 
Calocalanus pavo , and some smaller forms, along with half a 
dozen one-inch-long Heteronereids of a reddish-brown colour. 
The light was thought to be probably due to the last named, and 
if that is so possibly the periodicity was a result of the epitokous 
condition, and was accompanied by a simultaneous discharge of 
genital products. The matter, however, could not be made certain 
at the time, and the above explanation is only suggested. 
8. On the Origin of Adam’s Bridge. (By J. Lomas, A.R.C.S., 
F.G.S.f)—Stretching across from the north part of Ceylon to the 
south-east coast of India lies a remarkable chain of low-lying islands 
and shallow banks known as Adam’s Bridge. Rameswaram Island 
forms the most westerly link of the chain, and is only separated 
from Tonitoray spit (India) by Paumben straits, a shallow natural 
opening which has been deepened in parts by man. Mannar 
Island, at the extreme east of the bridge, lies close to the north¬ 
west coast of Ceylon. Between these a number of smaller islands 
* From Rep. Brit. Assn. (Southport, 1903), p. 695. 
f Reprinted from Rep. Brit. Assn. (Southport, 1903), p. 721. 
