64 
3. Pareuta Forsesit, Supplementary plate, f. 1, 2. 
Patella Forbesii, Smith, Wernerian Mem., VIII, p. 59, pl. 
Digsy aoe 
Shell thin, pellucid, obovate, gibbous, orange-coloured ; with 
regular, longitudinal, tuberculous striae; vertex inclined, inflect- 
ed. Length two-tenths of an inch; breadth one-eighth. 
“The regular, tuberculated, longitudinal strie, radiating from 
the submarginal apex, at once distinguish this species from any 
of its allies among the British Patelle. 
the Lottia pulchella. 
cated, and the colour of the shell is orange-yellow. 
In form it resembles 
The margin behind the apex is trun- 
When the 
animal shall have been examined, it may prove to be a Lottia.” 
Forbes. 
Dredged in Rothesay Bay, by James Smith, Esq., of Jordan 
Hill, adhering to a case-bottle in ten fathoms water. 
4. PATELLA PELLUCIDA, pl. XX, f. 2, 3, 7, 8, and 11. 
Patella pellucida, First Ed., pl. 37, f.11; Linné, Syst., p. 
1260; Da Costa, p.7, pl. 1, f.53; Pennant, p. 150, pl. 90, f. 
150, right hand fig., and f. 152, bottom fig.; Patella levis, 
Lamarck, VI, pt. 1, p. 334; Da Costa, p. 7, pl. 1, f. 5; Mon- 
tagu, p. 474; Maton and Rackett, p. 233; Brown, Wernerian 
Mem., II, p. 538; Ib., Ency. Brit., p. 465; Fleming, Brit. An., 
p. 287; Ib., Edin. Ency., p. 65, pl. 204, f. 2, 3, young; Turton, 
Brit. Fau., p. 197; Forbes, p. 36. 
Shell smooth, subpellucid, thin, yellowish-green; back con- 
vex, elegantly rounded; with an inclining vertex, which is placed 
nearer one end; from the superior portion behind the vertex 
emanate a series of beautiful azure-blue, translucent, interrupt- 
ed rays, irregular in point of number, varying from three to 
seven, and terminating on the margin; some nearly obsolete, 
concentric wrinkles traverse the shell; aperture oval; margin 
plain, inclining slightly upwards at both ends; inside glossy, of 
a bluish opalescent cast of colour, changing in hue according to 
Length one inch; breadth nearly three- 
quarters; height five-eighths. 
the play of light. 
Patella elongata and Patella parva, Fleming, Edin. Ency., 
p- 65, pl. 204, f.2, 3; (pl. XX, f. 2, 3, and 7) Patella bima- 
culata, Montagu, p. 482, pl. 13, f.6; Turton, Brit. Fau., p. 
197; Maton and Rackett, p. 235. (pl. XX, f. 7.) 
The young shell, pl. XX, f. 2, 3, 7, 8, is extremely thin and 
brittle, and of a much paler colour than the adult, usually of a 
yellowish horn-colour. 
This species inhabits most of the coasts of Great Britain and 
Treland, generally adhering to the Fucus digitatus, alge, and 
other marine plants. 
Much difference of opinion exists respecting this and the fol- 
lowing shell being of one species. As far as my observation 
has gone, I am inclined to consider them as different ; because 
I have met with shells of all ages, agreeing with each in its 
specific distinctions. The young of the following species is 
invariably thicker, and always depressed like the adult; and, 
moreover, the P. pellucida is always found on the leaves of the 
plants, while the P. c@rulea inhabits the stems or roots. 
My friend William Nicol, Esq., of Edinburgh, has a most 
perfect series of both shells, from the very youngest condition 
to the most mature, which beautifully illustrates the subject. 
At the meeting of the British Association, held at Manches- 
ter, in 1842, Mr. Peach, of the Preventive Service at Ghoran 
Haven, Cornwall, read a Paper, and exhibited specimens to 
MOLLUSCA. 
[ GASTEROPODA 
prove their identity, but I did not think he established his 
views on the subject. 
5. PaTELua cHRULEA, pl. XX, f. 13. 
Patella cerulea, First Ed., pl. 37, f. 13; Fleming, Edin. 
Ency., VII, p. 65, pl. 204, f. 1, adult, 1 a, young shell; Pen- 
nant, pl. 90, f. 150, left hand fig., young; Brown, Wernerian 
Mem., p. 533; Ib., Ency. Brit. p. 465; Forbes, p. 36; Mon- 
tagu, Sup., p. 152; Patella pellucida, Montagu, Sup., p- 475 5 
Donovan, I, pl. 3, f- 1; Maton and Rackett, p. 234, the adult 
shell; Da Costa, pl. 1, f. 6. 
Shell depressed, rather opaque, thick, slightly ovoid, of a 
yellowish-brown colour ; vertex flat, much rounded, and situate 
near to one end; concentrically wrinkled, with a series of pale 
azure-blue, shining, interrupted radii, which extend from the 
vertex to the base, and generally, also, on the sides; aperture 
subovate, opalescent, shining, blue internally; lips rather thick- 
ened. Length one inch; breadth eight-tenths; height five- 
tenths. 
Inhabits most of the British and Irish coasts, attached to the 
stems and interstices of the roots of alge, Fucus digitatus, &c. 
Genus 17.—Lorr1a.—Gray: 
Shell patelliform, rather depressed; vertex obtuse, for the 
most part placed considerably towards one end, pointing to the 
posterior margin; muscular impressions not symmetrical, but 
widest on the right side, towards that portion of the shell where 
the head of the animal is situate; aperture generally rather cir- 
cular; the central disc usually of a deep brown, variable in 
intensity; with a flattish internal margin. 
The shells of this genus so closely resemble those of Patella, 
that they are with difficulty distinguished. They are, however, 
generally flatter. The animal is very distinct from that of Pa- 
tella. 
1. Loria TEstupiNnaLts, pl. XX, f. 9, 10. 
Patella clypeus, First Ed., pl. 37, £..9, 10; Patella testudi- 
nalis, Miiller; Fabricius, Fau. Greenland, p. 385; Forbes, p. 
34; Patella Clelandi, Sowerby ; Smith, Wernerian Mem., VIII, 
p- 43. 
Shell oval, subdepressed; with numerous, fine, divergent, 
slightly waved, and rather regular strie, emanating from the 
slightly acute, reflected vertex, and terminating on the mar- 
gins; these are crossed by extremely numerous, and very 
close, concentric striz, and somewhat distant, more conspicuous 
lines of growth; external surface of a pale fawn colour, beau- 
tifully mottled with dark, reddish-brown, surrounding oblong- 
ovate, rather regular eye-like spots of the ground colour; inside 
very glossy, bluish-white; margin a little flattened, and orna- 
mented with nearly equidistant, dark brown spots; centre with 
an intensely dark, reddish-brown, well defined, large mark, sur- 
rounded by an indistinct disk of pale brown. 
First discovered as British by Stewart Ker, Esq., in the Gare 
Loch, on the Clyde, and has since been met with in different 
parts of Argyleshire; and Professor Forbes found it at Bal- 
laugh, Isle of Man, under the surface of stones at very low 
water. 
2. Lorria PULCHELLA. 
Lottia pulchella, Forbes, p. 35; Ib., Mag. Nat. Hist., VIIT, 
p- 591, f. 61. 
