PANDORA,
25
an erect cardinal, set at a right angle with th^ hinge-line, and
in the left valve a longer and somewhat horizontal cardinal,
set at an acnte angle with the uj^per margin of the anterior
side ; the teeth and cartilage are on opposite sides of the beak,
and diverge from each other : inside highly polished and iridescent, slightly striated in a radiating direction ; edges thin
and sharp : scars more or less distinct, according to the thickness of the nacreous lining. L. 0*6. B. 1*25.
Yar. 1. tenuis.
Shell much smaller, and of a delicate texture, proportionally broader or more produced at each end, with
an oblique and iiexuous outline ; dorsal margin straight.
Var. 2. ohtusa. Shell smaller and thinner, longer in proportion to its breadth; the posterior side larger, and not so
much produced or extended ; dorsal margin also straight.
Monstr. Shell oval, with the sides shorter than usual
dorsal margin projecting a little outwards.
Habitat : In sand, Channel Isles, at the recess of
spring tides, and in shallow water ; often among Zostera
marina. Var. 1. Between 85 and 100 f. off Unst in
Shetland.
Var. 2. From 7 to 50 f. on all our coasts.
The monstrosity is from the Hebrides and Shetland.
In a fossil state the typical form occurs in the Coralline
Crag, and the variety obtusa in the Red Crag ; both are
noticed by Philippi from different parts of the tertiary
formation in Sicily. The first has only a southern range,
from Guernsey to the ^gean ; while the distribution of
the other is wider, reaching to the Canaries in the
same direction, and extending northward to Spitzbergen.
In the ^Egean, Forbes gave 4 f. for P. iricequivalvis, and
71-10 f. for P. obtusa ; and at Mogador M^Andrew
recorded the respective depths of 3 f. and 35-40 f. for
the two forms. The observations made by M. Martin
in the Gulf of Lyons showed similar results.
The animal is shy and easily alarmed. Lacaze-Duthiers, in his valuable essay on the development of the
gills in LameUibranchiate Conchifera (Ann. Sc. Nat. 4^
VOL. III.
c
25
an erect cardinal, set at a right angle with th^ hinge-line, and
in the left valve a longer and somewhat horizontal cardinal,
set at an acnte angle with the uj^per margin of the anterior
side ; the teeth and cartilage are on opposite sides of the beak,
and diverge from each other : inside highly polished and iridescent, slightly striated in a radiating direction ; edges thin
and sharp : scars more or less distinct, according to the thickness of the nacreous lining. L. 0*6. B. 1*25.
Yar. 1. tenuis.
Shell much smaller, and of a delicate texture, proportionally broader or more produced at each end, with
an oblique and iiexuous outline ; dorsal margin straight.
Var. 2. ohtusa. Shell smaller and thinner, longer in proportion to its breadth; the posterior side larger, and not so
much produced or extended ; dorsal margin also straight.
Monstr. Shell oval, with the sides shorter than usual
dorsal margin projecting a little outwards.
Habitat : In sand, Channel Isles, at the recess of
spring tides, and in shallow water ; often among Zostera
marina. Var. 1. Between 85 and 100 f. off Unst in
Shetland.
Var. 2. From 7 to 50 f. on all our coasts.
The monstrosity is from the Hebrides and Shetland.
In a fossil state the typical form occurs in the Coralline
Crag, and the variety obtusa in the Red Crag ; both are
noticed by Philippi from different parts of the tertiary
formation in Sicily. The first has only a southern range,
from Guernsey to the ^gean ; while the distribution of
the other is wider, reaching to the Canaries in the
same direction, and extending northward to Spitzbergen.
In the ^Egean, Forbes gave 4 f. for P. iricequivalvis, and
71-10 f. for P. obtusa ; and at Mogador M^Andrew
recorded the respective depths of 3 f. and 35-40 f. for
the two forms. The observations made by M. Martin
in the Gulf of Lyons showed similar results.
The animal is shy and easily alarmed. Lacaze-Duthiers, in his valuable essay on the development of the
gills in LameUibranchiate Conchifera (Ann. Sc. Nat. 4^
VOL. III.
c