THE AUSTRALIAN MUSEUM MAGAZINE. 



235 



A Cuttle bone ; the internal shell of Sepia. 



[Photo. — G. C. Ctutton. 



The Sepia has its English name from 

 the way it " cuddles " down to rock or 

 sand on the sea floor. An exquisitely 

 graceful hull, with a texture like the 

 finest porcelain, is constructed by the 

 Paper Argonaut . A fairy tale told how 

 the molluscan mariner hoisted a sail 

 upon this dainty craft and sailed away 

 across the summer seas. But in truth 

 the shell of this Paper Argonaut is not 

 a dwelling as other shells are, but a nest 

 in which the eggs are laid and hatched 

 while carried about in mid-ocean, 

 clasped in the mother's arms. Finally, 

 the octopus or polypus has out-grown 

 its shell, leaving no trace of it either 

 within or without. 



Cephalopods are more highly organ- 

 ised than other members of the mol- 

 luscan family. Indeed, no other inver- 

 tebrates are so elaborately constructed, 

 furnished with so quick an eye, so 

 sharp a tooth, so long an arm, or so 

 cunning a brain. Probably a cephalo- 

 pod is more than a match for anything 

 its weight in the marine world. If 



pursued by a stronger foe, none can 

 dart quicker through the water ; should 

 speed avail not, the resourceful cephal- 

 opod discharges an inky cloud of sepia, 

 in which it disappears. 



(yommonest of the Cephalopoda is 

 the octopus. When seen at rest in an 

 aquarium tank, the large flabby body 

 of the octopus is bag-shaped ; it con- 

 tracts and expands as the animal j)ants 

 heavily. Round it are curled the long 

 arms, of which the inrer sides are beset 

 with a double row of disks, tapering 

 down from the size of a shilling at the 

 base to the tiniest dot on the tips. 

 These are the suckers ; when their 

 surface is applied to anything they 

 contract, and by pneumatic action ob- 

 tain the firmest possible grasp. Below 

 the arms there is on either side a bulging 

 eye with a narrow slit-like pupil. 



At rest, this octopus imitates in form 

 and colour the ground on which it lies, 

 till it becomes almost invisible. It 

 smoothes its skin, or puckers it, fades 

 or blushes, till it has assumed the 

 appearance of some particular dark 

 rough rock or smooth gray sand, on 

 which it chances to be. Around the 

 entrance of its den is stre^vn the refuse 

 of the hunt, heaps of broken shells and 

 bones, for the cctopus is a voracious 

 animal which greedily devours fish, 

 crabs, or cockles. 



Paper Nautilus ; a cradle, not a boat as is 

 generally considered. 



[Photo.— G. C. Chiiton. 



