328 Scientific Intelligence. 
selves in the.first spiral coil of O. tenuissima are what constitute 
the essential difference between the spire of Cornuspira and that 
of Spiroloculina; marking an aes septal division of the 
spire into chambers, which cannot be conceived to affect in any 
) 
assumption of the Peneropline stage. Again, the incipient widen- 
ing-out of the body, previously to the formation of the first 
complete septum, prepares the way for that great lateral exten- 
sion which characterizes the next or Orbiculine stage ; this exten- 
“In. 0; ir te et the first spiral sta 
ct ng-together (as it were) of the ‘spiroloculine’ coil into a 
siieeha spiral stage is fully retained. In V. duplex, the abbreviated 
Milioline center is still retained, but the succeedin bi 
spiral is almost entirely dropped out, quickly giving tegee o the 
eyclical plan. And in the typical O. complanata the Milioline 
center is immediately surrounded by a complete annulus, 80 
that ren remains “ ~ Sha ae spire save the one turn 
