THE CEYLON PEARL-OYSTER. 341 
LXXXYV 4, had its central cavity lined with hypostracum, as in 
the pearls described from the unlabelled specimens in the British 
Museum. The other had a central cavity lined on one side by 
a hilum-like plug of hypostracum, giving the pearl a reniform 
outline, and on the opposite side by columnar substance, going 
over into nacre. ‘wo of these muscle-pearls were composed of 
several fused units. 
There remain three pearls which have some claims to be treated 
as parenchyma-pearls. One of these, which was not sectioned, had 
in its centre a string of brownish granular matter, -66 mm. long 
by -17 mm. wide, of doubtful origin (Preparation LXXXV 0). 
Another (text-figure 41, A & B, Preparation LXXXV 1) had 
a pseudo-nucleus *1 mm. in diameter, which, examined entire, 
might have been taken for the remains of a minute Platy- 
helminthian parasite, but which on section proved to be made 
up in great part of amorphous repair-substance. Finally, one 
peari (Preparation LXXXV xk), a round pearl just under 2 mm. 
in diameter, possessing apparently all the external qualities 
of a parenchyma-pearl, had for its centre a pseudo-nucleus of 
stratified columnar substance, 1 mm. in diameter, surrounding 
a sand-grain 35 mm, in diameter. 
G. Pearls from Margaritifera vulgaris from the 
Gulf of Kutch. 
Being for the moment unable to obtain freshly preserved 
material from Ceylon or Madras, I endeavoured to obtain examples 
of the same species, preserved with pearls in situ, from Northern 
India, and through the courtesy of His Highness the Jam Saheb 
of Nawanagar, better known to most people in this country as 
Prince Ranjitsinhji, I was supplied in October last with a valuable 
collection of preserved oysters, containing pearls, from the 
Nawanagar fishery. I wish here to record my indebtedness to His 
Highness, and to Mr. Merwanji Pestonji, Dewan of Nawanagar, 
for their help. My thanks are also due to Dr. G. A. Grierson, 
C.1.E., Director of the Linguistic Survey of India, and to Mr. R. 
KE. Enthoven, LC.S., for putting me in communication with the 
Authorities of the State. 
The detailed histological examination of this material will take 
some time, but I have decalcified and sectioned a number of pearls, 
free and in situ, for purposes of comparison with the material from 
other sources. 
As the Nawanagar fishery is littie known to biologists, the 
following information, supplied to me by the Dewan, may be of 
interest. 
The fishery, which belongs to H.H. the Jam Saheb, is carried 
on on the southern shore of the Gulf of Kutch, during the South- 
West Monsoon season, from June onwards. The ground on which 
the pearl-oyster is found is ‘* usually the sloping bank of a reef, 
facing east or south-east, consisting of shingly sand and small 
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