15 



constant succession of muscular jerks, driving the keel of the shell with 

 great violence against the side of the pail. They rarely lived more than a 

 day or two^ and by sliaking them out of the shell they died in a few hours, 



From the delightful intercourse and correspondence which I have enjoyed 

 with my excellent fiiend on the subject of this vexata cmimaHa, I should 

 suppose the Argonaut to be an animal exceedingly sensitive of danger ; that 

 under any alarm the velamentous arms are partially, if not altogether, with- 

 drawn through the lateral nicks of the shell, and that under these circum- 

 stances it has great difficulty in maintaining its attachment. It has, more- 

 over, been estabhshed beyond the possibihty of contradiction, that the ani- 

 mal being disengaged from its shell has not the power of re-entering it ; 

 and that being liberated, it languishes and dies in the course of a few hours. 



The geograpliical distribution of the Argonaut is confined, as far as we 

 know at present, to the old world ; the A. argo is an inhabitant cliiefly of 

 the Mediterranean, and the A. tuberculosa of the Cape of Good Hope, New 

 Holland, and the Molluccas. I have not seen the animal of the latter 

 species ; it was, however, figured more than a hundred years ago by Eum- 

 pliius"^, and Dr. Hooker, the learned author of the 'Flora Antarctica', 

 informs me that several living specimens were seen during the Antarctic 

 Expedition off the Cape of Good Hope. 



Aegonauta aego. Plate A. — View of the animal having relaxed its 

 prehensile embrace of the shell and about to die, showing the eight 

 arms with two rows of suckers on each, the two front of wliich are 

 represented with the membranous webs contracting, to the left ; the 

 mouth and horny mandibles, in the centre ; and the funnel or organ 

 of secretion, to the right ; «, a sucker, enlarged. Frotn a specimen 

 taken alive at llessina hy the Rev. L. B. Larking. 



Plate B. — View of the animal in full health and vigour under water, 

 showing the manner in which it swims with the shell, keel foremost, 

 held within the embrace of its velamentous arms. Frmn the figure of 

 a specimen ohserved at Algiers hy M. Rang, slightly altered from ob- 

 servations made by the Rev. L. B. Larking at llessina. 



Species, f 



1 . argo, Llrin. B.havLstrnm, E. 3IeVi. 5. ravicosta, Blamv. 



2. cymbium, Zimi. 4. nitida, Lam. 6. tuberculosa, Lam. 



* Thesaurus imaginum, &c., pi. sviii. f. 1 to 3. Tlie Hague, 1739. 



t For references to where the species throughout the work are described aud figured, syno- 

 nymes, &c., see ' The Conchologist's Nomenclator ' by Agues Catlow. 



