LYONSIA.
31
from the newer tertiaries of Sicily. Its foreign range
in a living state comprises tlie Sea of Ocliotsk, and the
coasts of Iceland, Scandinavia, France, Italy, Algeria,
Greece, and jNIadeira, at depths varying from 10 to 70 f.
in northern, and from 4 to 70 f. in southern latitudes.
Miss Hutchins is the reputed discoverer of this remarkable and interesting shell.
According to Clark
the gills consist of a single leaf on each side ; the tubes
appear to be enclosed in one sheath, which has the
margin finely dentated ; and each orifice is garnished
with about eight white simple cirri, and as many black
equidistant points at their external edges.
He has not
mentioned the filaments at the base of each tube. Such
discrepancies are extremely perplexing ;. and if the identification of any species depended solely on characters
aftbrdcd by the soft parts, the study of conchology would
be almost impracticable. The faculty and means of
ol)servation, as well as the good faith possessed by Mr.
Clark, w^ere certainly not inferior to those which I have
exercised ; and yet how different is the result ! The
microscopic pustules covering the surface of the shell
appear to be the ends of the tubes which compose the
outer layer ; these are open in the young, and closed in
the adult.
The inner layer is entirely nacreous. The
shells are occasionally found in the stomach of the red
gurnard.
Dr. Lukis supposed that the young disguise
themselves in their sandy coating more completely than
the adult; but this is not always the case. The epidermis is of a gelatinous or viscous nature, and thus
grains of sand as well as organic particles become
attached to it.
It is the Mya nitida of Fabricius (but not of Miiller)
M. striata of Montagu, Amphidesma corbuloides of Lamarck, Mya pellucida and Myatella Montagui of Brown,
31
from the newer tertiaries of Sicily. Its foreign range
in a living state comprises tlie Sea of Ocliotsk, and the
coasts of Iceland, Scandinavia, France, Italy, Algeria,
Greece, and jNIadeira, at depths varying from 10 to 70 f.
in northern, and from 4 to 70 f. in southern latitudes.
Miss Hutchins is the reputed discoverer of this remarkable and interesting shell.
According to Clark
the gills consist of a single leaf on each side ; the tubes
appear to be enclosed in one sheath, which has the
margin finely dentated ; and each orifice is garnished
with about eight white simple cirri, and as many black
equidistant points at their external edges.
He has not
mentioned the filaments at the base of each tube. Such
discrepancies are extremely perplexing ;. and if the identification of any species depended solely on characters
aftbrdcd by the soft parts, the study of conchology would
be almost impracticable. The faculty and means of
ol)servation, as well as the good faith possessed by Mr.
Clark, w^ere certainly not inferior to those which I have
exercised ; and yet how different is the result ! The
microscopic pustules covering the surface of the shell
appear to be the ends of the tubes which compose the
outer layer ; these are open in the young, and closed in
the adult.
The inner layer is entirely nacreous. The
shells are occasionally found in the stomach of the red
gurnard.
Dr. Lukis supposed that the young disguise
themselves in their sandy coating more completely than
the adult; but this is not always the case. The epidermis is of a gelatinous or viscous nature, and thus
grains of sand as well as organic particles become
attached to it.
It is the Mya nitida of Fabricius (but not of Miiller)
M. striata of Montagu, Amphidesma corbuloides of Lamarck, Mya pellucida and Myatella Montagui of Brown,