Gesophageal Teeth of the Stromateidee. Zo 
attached to its centre was one of the tooth-like processes 
which line the interior of each sac, and it was at first supposed 
that the placoid nature of the teeth was thus evident. On 
further examination, however, no lines of growth were seen 
in the scale, it was unaffected by acid, and, on boiling in 
caustic potash, it was seen to be made up of a somewhat 
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f'mm. 
One of the tooth-like processes of the cesophageal sacs of 
Psenes natalensis. 
reticulate fibrous sheet of clear horny-looking tissue. Towards 
the periphery this substance was homogeneous, and near the 
centre fibres could be seen passing upwards to form the long 
“tooth” (text-fig. 1). On its upper two-thirds there were 
short offshoots, each capped with a hollow, sharp, curved 
spine, the longest being about °33 mm, They thus differ 
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