(56 
* C. EUROPyEA. C. Pediculns. Turt. Lin. Borlase’s Nat. 
Hist. Corn., pi. 28, fig. 12. Stew. Elera., vol., 2, p. 397. 
Mont. Test. Brit., vol. 1, p. 200. C. E. Flem. Brit. An-? 
p. 330. In its young state this is altogether unlike the 
perfect shell, and constitutes the C. Bullata of Montage, 
Test. Brit., vol. 1, p. 202, pi. G, fig. 1. In this conditio" 
they differ greatly in size; hut whatever be the magnitude 
obtained, the further progress towards the perfect mark- 
ings is not accompanied with enlargement: so that many 
matured shells are much smaller than others in their first 
growth. When the form and striation are in the inter- 
mediate state, they constitute the Cypraea Arctica 
Montagu, vol. 1, p. 201. These changes are rapid*/ 
passed, and take place about the end of summer. Co®' 
raon, and often found with the animal, in crab-boats. 
Cornish specimens are usually smaller than those farther 
east. 
CEPHALOPODA. 
POLYTIIA LA MO US CEPHALOPODA. 
The shell many chambered, more or less enveloped, placed 
on the hinder part of the body of the animal, often adhering- 
FIRST DIVISION. 
The shell many chambered, the partitions simple; not 
showing any divided sinnous sutures on the inner surface ® 
the shell. 
OR T HOG ERA TA. 
The shell straight or nearly so ; not spiral. 
ORTHOCERA. 
GENERIC CHARACTER : The shell straight or slightly 
arched, subconical, striated on the outside by numerous 
longitudinal ribs; chambers formed by transverse partitions? 
perforated by a central or marginal tube. 
O. IMPERFORATA. Dentalium I. Turt. Lin. Mo®* 
Test. Brit., vol. 2, p. 496. O. I. Flem. Brit. An., p. 2<I'* 
Found by Montagu in sand at Falmouth. 
O. RECTA. Nautilus Rectus. Mont. Test. Brit., vol. D 
p. 197. O. R. Flem. Brit. An., p. 236, Usually con- 
sidered exceedingly rare ; hut in a few instances I b il ' ,e 
found it. adhering to the shell of a Pinna from deep water? 
and suppose it not uncommon, though from its small s * ze 
commonly overlooked. 
LITUOLATA. 
. ^ 
The shell partly spiral, the last whorl continuing ,Q 
straight line. 
