106 
4. AMPHIDESMA TRUNCATA, pl. XLII, f. 4. 
Ligula truncata, First Ed., pl. 14, f. 4; Amphidesma trun- 
catum, Fleming, p. 431. 
Shell subovate, rather convex, oblique; anterior side pro- 
duced ; posterior side rather straight, and subtruncated below; 
with a flexure, emanating from the umbo, and terminating on 
the margin; umbones small, nearly central, and slightly in- 
flected, beneath them a lanceolate cavity or lunule, covered 
with transverse, nearly obsolete striae, and wrinkles; surface 
white, smooth, and glossy; hinge with a double primary tooth 
in each valve, and a small tooth-like knob in the left valve, 
locking into a cavity for its reception in the opposite one; in- 
side smooth, glossy, and white; each valve provided with two 
large muscular impressions; margins rather thick, for the size 
of the shell. Length three-eighths of an inch; breadth half 
an inch. 
Found at Greenock, by Stewart Ker, Esq., and is in the 
cabinet of Lady Jardine. 
Genus 32.—Licuta—Montagu. 
Shell inequivalve, inequilateral, transversely elongated; with 
a large, broad, strong, transverse, spoon-like tooth in each valve, 
projecting inwards, each furnished with a pit for the insertion of 
the cartilage; right valve furnished with a pretty large, elevated, 
erect, compressed tooth, situated close below the beak, fitting 
into a hiatus for its reception, which reaches to the beak, in 
the opposite valve; and in some species a minute tooth; exter- 
nal surface with a very thin, membranaceous epidermis; two 
muscular impressions in each valve, situate very close to the 
extreme sides of the valves, the posterior ones double, and ex- 
tending to nearly the umbones; pallial impression with a rather 
large, transverse sinus, situated posteriorly. 
1. LicuLa preTenuis, pl. XLII, f. |. 
Ligula pretenuis, First Ed., pl. 14, £13; Anatina prete- 
nurs, Turton, Biy., p. 48, pl. 4, f.4; Amphidesma pretenue, 
Fleming, p. 432; Bontea pretenuis, Leach, MSS., p.6; Mya 
pretenuis, Montagu, p. 41, pl. 1, f. 2; Donovan, V, pl. 178. 
Shell oval, thin, very brittle, compressed, and semipellucid ; 
umbones nearly central, very small; beaks rather acute, and 
inflected ; posterior side rounded; anterior side somewhat acu- 
minated, and obliquely subtruncated, at which extremity the 
valves are a little open; surface cream-white, transversely 
wrinkled, with extremely fine, nearly obsolete, concentric strie, 
covered with an extremely thin, cream-coloured, somewhat 
pilous epidermis; hinge with a broad, horizontal, internally 
projecting, hollow tooth in each valve; inside white. Length 
about half an inch; breadth somewhat more than an inch. 
This rare British shell has been found at Poole, and other 
places on the Dorsetshire coast; the south coast of Devon; 
Frith of Forth; and Portmarnock, Ireland. 
Genus 33.—TELLIMyA.—Brown. 
Shell equivalve, inequilateral, suborbicular, or transversely 
elongated, close all round; left valve destitute of cardinal teeth, 
but provided with a pretty large hiatus, and two projecting 
lateral teeth, each having a groove in its centre; sometimes 
with one or two rather long teeth on the right side; right valye 
MOLLUSCA. 
[Macrracga. 
with two recurved, prominent teeth, which occupy the vacant 
space below the umbo in the opposite valve; muscular impres- 
sions large and distinct ; pallial impression entire. 
Section I.—Shells orbicular. 
1. TELLIMYA suBOoRBICULARIS, pl. XLII, f. 14, 15. 
Tellimya suborbicularis, First Ed., pl. 14, f. 14, 15; Mya 
suborbicularis, Montagu, p. 39, pl. 26, f.6; Maton and Rackett, 
VIII, p. 41; Kellia suborbicularis, Turton, Biv., p. 57, pl. 
11, f. 5, 6; Fleming, p. 430; Forbes, p. 49; Bomia inflata, 
Phillipi. 
Shell suborbicular, very convex, thin, subpellucid; umbones 
obtuse, nearly central, slightly inflected; sides almost equal, 
rounded ; basal margin nearly parallel; surface of a yellowish- 
white colour; somewhat glossy, with faint concentric stria ; 
hinge with a single tooth in one valve, immediately under the 
beak, locking into a double incurved one in the opposite valve, 
with a somewhat laminated tooth behind the umbo in each 
valve; inside glossy, white. Length three-eighths of an inch; 
breadth half an inch. 
Some specimens exhibit a fine pearlaceous lustre, when de- 
prived of the epidermis. 
fuhabits the Frith of Forth, Plymouth, Saleomb Bay, and 
coasts of the Isle of Man. It is a borer, and penetrates the 
hardest limestone; Forbes found it in the cavities of dead 
bivalves. 
2. Te.uimya LacTEa, pl. XLII, f. 10, 11. 
Tellimya lactea, First Ed., pl. 14, f. 10, 11; Brown, Conch. 
Text Book, p. 138, pl. 17, f. 14. 
Shell nearly orbicular, inflated, thin, pellucid, and glossy 
white; one valve with two teeth, locking into a triangular void 
in the opposite valve, with transverse lamine on each side; left 
valve with a single, recurved, cardinal tooth, and a central, tri- 
angular, lamellated tooth; and one remote, lateral tooth only. 
About a quarter of an inch in diameter. 
Found on the Devonshire coast, by Dr. Leach. : 
3. TELLimya TENUIS, pl. XLII, f. 12, 13. dubortre 
Tellimya tenuis, First Ed., pl. 14, f. 12, 13. 
Shell orbicular, smooth, glossy, snow-white, with fine, irregu- 
lar, concentric stria, much inflated; umbones rather produced, 
and much turned to one side; left valve destitute of cardinal 
teeth, but provided with two large lateral teeth; right valve 
with two incurved, cardinal teeth, and a lateral one; inside 
white, and when viewed through a strong lens, has a shagreen- 
like appearance. Diameter three-eighths of an inch. 
Found at Newbigging, Northumberland, by W. C. Trevelyan, 
Esq., and is in the cabinet at Wallington. 
Section II.—Shells transversely ovate. 
4, TELummya ELiptica, pl. XLII, f. +6;,47. / 7 
Tellimya elliptica, First Ed., pl. 14, f. #6; 19; Mya ferrugi- 
nosa, Montagu, Sup., p- 22 and 166, pl. 26, f.2; Montacuta 
ferruginosa, Turton, Biv., p. 60. 
Shell transversely subovate, moderately ‘convex, white, with 
obsolete, concentric wrinkles, and sometimes blotched with rust- 
coloured spots; umbones obtuse, situate nearest one side; basal 
margin nearly parallel; hinge with two projecting teeth, one of 
which is erect, the other slopes inwards and downwards, these 
