ANATOMY- O r SCYLI^EAAND ETTMENII
Genus 9 bis. SCYUM3A, Ltnnjeus.
Corpus oblongum, lateribus valde compressis, dorso convexo, lobis magnis, biparibus, utrinque
cristato. Caput sub-inferius; maxillis corneis. Tentacula duo, anterioria, dorsalia, lamellata, intra
vaginas magnas, cristatas, retractilia. Branchial parvse, ramosse, in lobarum dorsalium facie interaft
sparsae. Pes linearis. Orificia generationis et ani ad latus dextrum.
The genus Scyllaa was established by Linnaeus, but was very imperfectly understood
until the time of Cuvier, whose elaborate Memoir upon the genus first placed its characters
and affinities in their true light, and left little to be’added by succeeding writers. Cuvier gives
some" curious instances of the mistakes made by the early naturalists with respect to the
animal on which this genus was formed. Seba, who was the first to publish it, took it for the
young of a fish, and figuring it in an inverted position, placed it in the genus Lophius; and
Linnseus himself, though he so far understood its affinities as to remove it to his class Vermes,
and to create for it a new genus, described the animal upside down; a mistake which was
followed by Gmelin, and copied by subsequent authors until near the time when Cuvier wrote
his m&noir. It was also supposed by some of the older naturalists, that the animal was permanently
fixed to 'the sea-weed on which it was found; an idea originating in the firm hold
which it takes of the stems of Fuci, to prevent its being dislodged by the force of the waves.
All authors describe the foot as deeply grooved, but this view of its formation is only- a remnant
of the old errors. From a knowledge of other mollusks with similar habits, we have little
hesitation in saying that the foot will be found perfectly flat when crawling on a level surface,,
but that, its sides being highly flexible, it is capable of grasping a cylindrical stem, as in other
allied genera, with great ease and firmness.
This genus includes only one or two species, but is widely diffused through the seas of
both hemispheres, to which its habit of living on floating sea-weeds mainly contributes. Its
recognition as an inhabitant of the British seas is but of recent date, but as the number of
observers increases, it will most likely be found more frequently on the Atlantic portion of our
coast.
Scyllaa is not more remarkable for its curious external form, than interesting on account
of its internal, an atomy. In it is observed the first distinct partition of the liver mass, as well
as an approach towards that branched form of the digestive organs so remarkable in the
Eolididce: for not only is the liver divided into globular, masses, as represented by Cuvier,
but from these masses ramifications proceed, which pass into the dorsal lobes, some of them
even penetfeting into the branchial tufts; a circumstance which has escaped the observation
of that great naturalist. Taken in connection with lendronotus and Fumenis, this genus
well illustrates the series of modifications by which one form of organ is gradually changed