112 
MOLLUSCA. 
[SOLENIDES. 
Shell strong, convex, subovate; umbones subcentral, or situate 
nearest the greatly truncated and shorter side, and vfhich gapes 
widely ; anterior side well rounded ; hinge line nearly parallel ; 
basal line hollow ; external surface with numerous, concentric 
wrinkles, covered with a yellowish-brown or drab-coloured epi- 
dermis, extending upwards of half an inch beyond the open 
end, in which situation the sides of the valves are a little 
reflected ; hinge with a broad, erect, strong, complicated tooth, 
with a spoon-like triangular cavity for the reception of the car- 
tilage, and several folds on the side ; inside smooth, white. 
A common shell on almost all the coasts of Britain and Ire- 
land; it lurks in sand to the depth of three or four inches. 
Family IX. — Solenides. 
Shells transversely elongated, destitute of accessory pieces, 
gaping at the lateral extremities ; ligament external. 
Genus 42 — Panop^a — Mesnard. 
Equivalve, oval, inequilateral, gaping unequally at both extre- 
mities ; hinge with an acute, primary tooth in each valve, and a 
large callosity near the umbones, supporting the ligament ; two 
distant, oval, muscular impressions; pallial impression with a 
large sinus; ligament large, external, adhering to an ample, pro- 
minent fulcrum. 
1. Panop^a Glycimeris, pi. XL VI, f. 1. 
Panopcea Glycimeris, First Ed., pi. 10,* f. 1 ; Mya Glyci- 
meris, Donovan, IV, pi. 142; Maton and Rackett, p. 34; Mon- 
tagu, Sup., p. 19 . 
Shell transversely elongated, very thick, and undulous ; with 
transverse wrinkles, and gaping widely at both extremities ; 
umbones large, elevated, obtuse, and nearly straight ; general 
colour of a cinereous or ochraceous hue ; hinge with a large, 
very thick, primary tooth, and a smaller one beside it, with 
several transverse folds. 
First discovered between the Dogger Bank and Eastern 
coast of England; Turton gives as a locality Teignmoulh; and 
Mr. Bean, of Scarborough, obtained one alive by dredging, off 
the coast of Scarborough, and also a dead specimen. 
Genus 43. — Solen. — Linnaeus. 
Shell equivalve, transversely elongated, subcylindrical, pro- 
digiously inequilateral ; umbones nearly terminal, situate close 
to the anterior side, and gaping widely at both extremities ; 
truncated, or subtruncated, sometimes rounded ; hinge linear, 
with several small cardinal teeth, various in form, often acute 
and recurved ; lateral teeth somewhat elongated and crooked ; 
muscular impressions distant, tongue-shaped, the anterior one 
joined a little behind the umbones ; the posterior one irregular 
and suboval; pallial impression elongated, straight and bifurcated 
behind ; ligament long and exterior ; external surface covered 
with a thick, horny epidermis. 
1. Solen Siliqua, pi. XL VII, f. 3, 3. 
Solen Siliqua, First Ed., pi. 13, f. 3; Montagu, p. 46; Dono- 
van, II, pi. 46; Turton, Biv., p. 80, pi. 6, f. 5 ; Fleming, p. 
459 ; Forbes, p. 55. 
Shell subcylindrical, straight, greatly inequilateral, obliquely 
truncated, and open at both sides ; hinge situate at one side, 
near the extremity, with a single, thin, compressed, upright 
tooth in one valve, and an elongated, remote, lateral lamina; the 
other valve with two teeth, a primary and a lateral inclined one, 
corresponding with the lateral lamina ; surface covered with an 
olivaceous-brown, strong epidermis, excepting on the greatly 
lengthened, diagonal, triangular area, which takes its rise at the 
umbones, and terminates on the opposite side, on this space the 
epidermis is thinner, and frequently of a lilac hue ; beneath the 
epidermis the shell is cinereous, and streaked with pale lilac or 
white; the lower area is striated transversely, with distinct lines 
of growth, both of which suddenly cross the area longitudinally, 
and define the divisions on the surface ; inside dull white, fre- 
quently tinged with purple. Varying from an inch to an inch 
and a quarter in length; and from seven to eight inches in 
breadth. I found a specimen at Holy Island measuring twelve 
inches. 
Inhabits most of the shores of Britain and Ireland, near low 
water-mark, burrowing to the depth of a foot in the sand, which 
it penetrates with astonishing rapidity. 
2. Solen Vagina, pi. XLVII, f. 2, 2. 
Solen Vagina, First Ed., pi. 13, f. 2; Montagu, p. 48 and 
565; Ib., Sup., p. 25; Turton, Biv., p. 79) pi. 6, f. 4; Fleming, 
p. 458; Solen marginatus, Donovan, IV, pi. 110. 
Shell straight, nearly cylindrical, truncated at both ends, that 
next the hinge somewhat oblique, reflected, and provided 
with a pretty deep, longitudinal furrow, emanating from the 
exterior side of the umbones, widening as it descends, and ter- 
minating on the margin ; a lateral, triangular area takes its rise 
on the superior or hinge line, at the umbones, and terminates 
on the posterior side, occupying about half the area of the 
shell, and dividing it, as it were, into two lengthened triangles ; 
whole surface covered with rather close, irregular stri®, these 
run horizontally on the lower area, and at their junction with 
the superior area, turn suddenly perpendicularly, and being 
reflected near the hinge line, terminate on the margin; a 
fine, rather thin, drab-coloured epidermis invests the entire 
shell, which, however, is frequently of an orange or ferru- 
ginous-colour near the umbones, extending considerably be- 
yond the basal margin, and posterior side ; umbones situate 
close to the anterior side; hinge with a single, compressed, 
elevated tooth in each valve, which lie close to each other 
when the valves are shut ; destitute of lateral teeth ; a large, 
lateral, and thickened lamina takes its rise from the base of 
the cardinal teeth in both valves, these are acute at both 
extremities; inside smooth, glossy, and of a purplish-white 
tinge. Ordinary length about three-quarters of an inch; 
breadth about four inches : although it frequently considerably 
exceeds that size. 
This is a very local species, and has been found near Laug- 
hare, Caermarthenshire ; Red Wharf, Anglesey; Weymouth; 
and is frequently met with in Dublin Bay, Portmarnock, Bal- 
brigsin, and Western coasts, Ireland. 
3. Solen Ligula, pi. XLVII, f. 2.* 
Solen Ligula, Turton, Biv., p. 81, pi. 6, f. 6. 
“ Shell straight, in one valve a single, compressed, obtuse, 
slightly cloven tooth, and two in the other.” — Turton, 
