265 
existence of immense Cephalopods in the seas of our own 
epoch, and show that the fears entertained by pearl 
divers, coral fishers, and bathers of the Polynesian islands, 
of being captured by these creatures, and enveloped in their 
snake-like limbs, armed with cupping instruments, hooks, 
and veritable claws, are not absolutely without foundation. 
Though the arms of Cephalopods doubtless assist in the 
function of locomotion, enabling them to crawl head down- 
wards over the rocks or along the sand of the sea floor, yet 
they aid them but little in the act of swimming ; this aid is 
afforded by other organs, viz., the Fins and the Funnel. 
The Fins are not found in all genera, and indeed are confined 
to the Decapoda ; they are fleshy, lateral expansions of the 
mantle. In Sepiola * and Eossia * they are latero-dorsal ; in 
Sepia they are lateral and narrow ; in Cranchia f Histio- 
teuthis, Onychoteuthis, Loligo and Ommastrephes, they are 
latero- terminal. 
The Funnel or Siphon is situated under the head at the 
point of its junction with the body ; in the Bibranchiafa it 
consists of a flexible tube, with continuous walls throughout 
its entire length, and is situated in the mantle cavity, from 
which it projects ; in the Tctrahmnchiata its edges are free, 
and the tube is formed by simply bringing these into contact. 
The Cephalopods swim backwards ; this motion is effected by 
the forcible expulsion of sea-water through the funnel and 
the consequent rebound of the animal in the water ; the 
funnel is provided with a valve which allows the expulsion of 
water, but prevents its return. The organ also assists in the 
function of respiration, for by it the liquid which has already 
aerated the blood, and consequently become charged with 
effete materials, is got rid of. 
* " Ont'.io Anafomyof tlieSc pi viil mris, Lca< h.''i;<'bci t Grant, Londi in, 18.13. 
t " Noglc nyo CephalopucU r bro.krovr.e og auatouiisk undcrso^jto af Victor 
TroBcb." Kjobcub, im. 
