1921.] The Eighth Indian Science Congress. exlvii 
the luminosity of some of the estuarine animals in the paniene: delta. 
Some doubtful records of the occurrence of this phenomena are r jected 
in view of the present investigations, and all authentic oe ed by 
m are ah at some length. 
ane on the occasional absence of a paired fins in fresh- 
ater fishes.—By Sunpar Lat 
The author refers to four abnormal specimens, three of which wigs 
recently pullaceed in Manipur. The abno ng consists in one casei 
the total absence of the ventral fins; in two other cases the ganiwrets Gate 
‘ de 
of genital variations or mutations in — he author regards them as 
cases of injury to the developing em The validity of the two apodal 
genera Channa and Apua is piper 5 5 ibe light of these observations. 
The fauna of the Loktak Lake in Manipur.—By N. 
ANNANDALE and 8. L. Hora 
The Loktak lake is a body of water occupying a shallow depression 
in the Manipur valley. It is almost choked with submerged vegetation 
r fy i ing islands Nontpossd 
ady. 
physical conditions are the same as those in the Talé lake in cy Se Fae niin 
Shan States, veal certain pea are different, notably the chemical 
i ie 
The fauna of at o lakes is totally different in facies and composi- 
That of the Loktak cars is entirely paludine. Certain species are 
very few of these are hips & specialized. e two most important groups 
are the fishes and the molluscs, for the. Tower invertobra tes are poorly 
w any real endemic element. 
s 
ble ver’ e but thi 
vagant sculpture of the Viv series of the Inlé lake. Neither species is 
confined to the Manipur valley. 
The external hag on of the shell in the Vivipa- 
ridae.—By N. ANNANDALE. 
rnamentation of the shell in — Se vse age aad - 
The o 
i iostracal (** igo , partly impre t 
ibe peros eee tn “th wrt at birth vie a important 
te positio 
hae 
acal. They disappear to a large e 
traces of them can usually be found. “The fully Aeveloped shell differs 
considerably in sculpture in different genera and S$ cies, but ~ ornamen- 
i ’ nt as in the embryonic shell, that is to say, 
llines. The sculpture, however, mainly 
horny chaetae arranged in three or wei spiral sia c 
entirely periostr in the adult, but 
ted by two sets of glands 
er layers of the she re 
8 edge of the mantle, namely, the periostracal gla: ands and 
the calciferous glands. Their functions are dicated in the names give 
: reg in — ith t aiid. we oe s — 
edge of the saan These ie as mou ods organ 
