PEDUNCULATA. | 
Genus 4——ScaLPELLUM—Leach. 
Shell laterally compressed, subquadrate, acuminated above ; 
and composed of thirteen valves, one pair acuminated and 
apicial, another pair ventral, two pair lateral, and an arcuated 
one on the back; attached to extraneous substances by a short, 
sealy, or hairy peduncle. 
1. ScaLPELLuM vuLcareE, pl. LI, f. 7, 9, 10. 
Scalpellum vulgare, First Ed., pl. 5, f. 7, 9, 10; Leach, 
Ency. Brit. Sup., Cirripedes, pl. 57; Ib., MSS., p. 1; Pol- 
Uicipes scalpellum, Lamarck, V, p. 407; Brown, Ency. Brit., 
VI, p. 403. 
Peduncle horn-coloured, scaly, attenuated below, and covered 
with smooth scales; shell compressed, provided with thirteen 
horn-coloured valves, with obsolete striz. 
Found on many of the British and Irish coasts, adhering to 
rotten timber, &c. 
Variety a, f. 7. Valves close, strongly striated concentri- 
cally ; peduncle with the scales set in regular rows. 
Scalpellum vulgare, Leach, Ency. Brit. Sup., pl. 57. 
Variety b, £.9. Valves considerably apart, substriated con- 
centrically ; peduncle with close-set, imbricated scales. 
In Lady Jardine’s cabinet. 
Variety c. Valves all separated, and concentrically substri- 
ated ; side valves with a central, projecting point ; peduncle 
with the scales set in regular annulations. 
Donoyan, pl. 166, f. 1. 
2. SCALPELLUM sMILium, pl. LI, f. 8. 
Scalpellum vulgare, First Ed., pl. 5, f. 8; Smilium Peronit, 
Sowerby, Conch. Man., p. 260, pl. 2, f. 36; Lepas scalpellum, 
Montagu, p. 18, pl. 1, f. 4. 
Shell consisting of thirteen smooth, light brown valves, ten of 
them in pairs, placed laterally, and subtriangular; one situated 
posteriorly; peduncle with annular, scaly processes, slightly 
imbricated, and beset with numerous, fine, short hairs. 
Found at Sandwich and Plymouth, in deep water. 
Genus 5,—PENTELASMIs.—Leach. 
Shell laterally compressed, conical, and composed of five 
valves, held together by a membraneous, ligamentary process ; 
lower valves the largest, of a subtrigonal form, a little convex, 
and acute at their anterior base; upper lateral pair elongated, 
and subquadrate, dorsal one lanceolate, carinated, and arcuated; 
seated on a peduncle, which is of variable length. 
1. PENTELASMIS ANSERIFERUS, pl. LI, f. 1. 
Anatifa striata, First Ed., pl. 5, f. 1; Lepas anseriferus, 
Montagu, p. 16; Donovan, pl. 166; Maton and Rackett, 
p- 28. 
Shell compressed, bluish-white, and glossy; larger valves 
somewhat inflated behind; four of them with strong, radiating 
stria, assuming the character of furrows towards the margins of 
the valves, which are crossed by very fine striz, giving them a 
faint reticulated appearance; angles of the valves sharp, espe- 
cially the apicial one; dorsal valve compressed at the sides, and 
brought to a fine carinated margin; superior valves much com- 
pressed, rendering the shell extremely thin and flat on the pos- 
terior side. Length an inch; breadth three-quarters. 
MOLLUSCA. 
119 
Found on drifted wood, on several of the British and Irish 
coasts. 
2. PENTELASMIS STIATUS, pl. LI, f. 4, 5, 6. 
Anatifa striata, First Ed., pl. 5, f. 4, 5, 6; Lepas sulcata, 
Montagu, p. 17, pl. 1, f. 6; Maton and Rackett, p- 29. 
Shell compressed, subtriangular; the inferior valves with fif- 
teen strong ribs, diverging from the lower anterior angle; that 
which runs along the front is larger than the others, and forms 
a margin; the two superior valves terminating above in an 
acutely pointed apex; with seven or eight ribs, and smaller 
intermediate ones, diverging from the posterior margin; dorsal 
valve somewhat compressed, with strong, longitudinal stria, and 
a smooth, subcarinated edge; colour yellowish-white; peduncle 
short, dusky. Length a quarter of an inch; breadth nearly 
the same. 
Found attached to Gorgonia flabellum, on the Dorsetshire 
coast, near Portland Island. 
Variety b, f. 5, 6. 
Lepas striata, Wood, Gen. Conch., pu 1645) ples Oy fa ais 
Leach, Ency. Brit. Sup., Cirripedes, pl. 57; Pentelasmis pumi- 
cicola, Leach, MSS., p. 1. 
Found on many of the coasts of Britain and Ireland, attach- 
ed in clusters to rotten wood, stones, &c. Montagu mentions 
its having been found on Gorgonia flabellum, near Portland 
Island. 
3. PENTELASMIS ANATIFERUS, pl. LII, f. 1, 2, 3, 4. 
Anatifa Levis, First Ed., pl. 4, f. 1, 2, 3, 4; Lamarck, V, 
p- 404; Pentelasmis anatifera, Leach, MSS., p. 1; Lepas ana- 
tifera, Pennant, IV, p. 74, pl. 38, f. 9; Donovan, I, pl. 7; 
Montagu, p. 15; Maton and Rackett, p. 28. 
Shell compressed, of a bluish-white, and very glossy; two 
lower valves somewhat triangular, longitudinally wrinkled, with 
nearly obsolete strie, radiating from the lower interior angle ; 
two superior valves elongated, and tapering to an obtuse point, 
upper portion angulated on both sides, apex rounded, these 
have likewise obsolete, radiating strie, and are longitudinally 
wrinkled from the upper posterior angle; dorsal valve long, 
slender, arcuated, smooth down the middle, and suleated on 
the sides; connecting cartilage and peduncle of a reddish- 
orange, frequently inclining to scarlet, the latter extremely 
variable in length, as will be seen from the different specimens 
figured; in a solitary instance, we met with it of a pale brown, 
as in fig. 1. 
Found attached to pieces of rotten wood, on many of the 
British and Irish coasts, and is the most common species of the 
genus. 
Fig. 2 and 4, the more ordinary form of the species. 
Fig. 1, more dilated, the dorsal valve appearing as if jointed. 
Fig. 3, a rare variety, with the larger valves more dilated than 
usual, and with strong stria. In the cabinet of Mr. Albany 
Hancock, Newcastle-upon-Tyne. 
4. PENTELASMIS DENTATUs, pl. LII, f. 5. 
Anatifa dentata, First Ed., pl. 4, f. 5; Lamarck, V, p. 405; 
Bruguiére, Dict., No. 3; Zepas dentata, Dillwyn, Cat., p. 32. 
Shell with very smooth, glossy valves, of a bluish-white ; 
agreeing in every particular with those of P. anatiferus, 
excepting the dorsal valve, which is provided with a series of 
oblique, saw-like teeth; peduncle short, and of a pale scarlet 
colour. 
