A manual of the Mollusca, or, A rudimentary treatise of recent and fossil shells . it iiifigured. 66 MANUAL OF THE MOLLTJSCA. suckers, 45 on eacli side; but no branchlce; the skin contains numerouschangeable spots of red or violet, like that of the argonaut.* According to the observations of Madame Power, the newly hatchedargonaut has no shell, and is quite unlike what it afterwai-ds becomes; it is asort of little worm, having two rows of suckers along its length, with a fili-form appendage at one extremity, and a small swelling at the other. It mightbe supposed to represent an extreviehj smal
A manual of the Mollusca, or, A rudimentary treatise of recent and fossil shells . it iiifigured. 66 MANUAL OF THE MOLLTJSCA. suckers, 45 on eacli side; but no branchlce; the skin contains numerouschangeable spots of red or violet, like that of the argonaut.* According to the observations of Madame Power, the newly hatchedargonaut has no shell, and is quite unlike what it afterwai-ds becomes; it is asort of little worm, having two rows of suckers along its length, with a fili-form appendage at one extremity, and a small swelling at the other. It mightbe supposed to represent an extreviehj small brachial appendage, fiom whichthe other parts were afterwards to be {Kolliker.)FAMILY I. ARGONAUTID^. Dorsal arms (of the female) webbed at the extremity, secreting a symme-trical involuted shell. Mantle supported in front by a single ridge on thefunnel. Genus Argonauta, Lin. Argonaut or paper sailor. Etymology, argonautai, sailors of the sliip Aigo. Synonyms, ocythoe (Rafinesque). Nautilus (Aristotle and Pliny). Example, A. hians, Soland, pi. II., fig. 1. Fig. 32. Argotiauta argo L. swimming.^The shell of the argonaut is thin and translucent; it is not moulded onthe body of the animal, nor is it attached by shell-muscles; and the imoccu-pied hollow of the spire serves as a receptacle for the minute clustered argonaut sits in its boat with its siphon turned towards the keel, § and itssail-shaped (dorsal) arms closely applied to the sides of the shell, as in fig. 32,where, however, they are represented as partially withdrawn, in order to showthe margin of the aperture. It swims only by ejecting water from its fun- * Similar instances of a permanently rudimentary condition of the male sex, oc-cur amongst the lowest organized parasitic crustaceans ; the males of achtheres, ler-ncEopoda, tracheliaster, §-c., are frequently a thousand times smaller than the female,upon whom they live, and from whom they differ both in form and structure. has
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Keywords: ., bookcentury1800, bookdecade1850, booksubjectmollusks, bookyear185
