112 



MOLLUSCA. 



[SOLENIDES. 



Shell strong, convex, subovate; umbones subeentral, or situate 

 nearest the greatly truncated and shorter side, and which 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^ea 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. 1 0,* 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 Teignmouth ; 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. XLVII, f. 3, 3. 



Sulen 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; lb., Sup., p. 25; Turton, Biv., p. 79, pi. 6, f. 4; Fleming, 

 p. 45S ; 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 strise, 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- 

 briggin, and Western coasts, Ireland. 



3. Solen Lioula, 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. 



