MOLLUSCA. 
121 
Sessilia.] 
Shell subcotiic, depressed ; with from seventeen to nineteen 
nearly equidistant, divergent, smooth ribs, extending consider- 
ably beyond the base, which is nearly circular; in some in- 
stances two or three are situate closer to each other than the 
rest ; aperture small, subovate, with its edge very regular and 
even ; operculum pale pink, four-valved, and very obtuse at the 
apex ; anterior valves striated obliquely. 
Not uncommon on many of the British and Irish coasts. 
The very distinct and charcteristic specimen from which we 
made our drawing of fig. 3, pi. LIV, was found at Seaton, 
Northumberland, by W. C. Trevelyan, Esq<, and is in the 
cabinet of Sir John Trevelyan, Bart., at Wallington. 
5. Balanus candidus, pi. LIV, f. 8, 9, 10, 11, 12. 
JBalanus Scoticus, First Ed., pi. 6, f. 8, 9> 10, 11, 12; Bala- 
nus candidus, Leach, MSS., p. 2. 
Shell conical, nearly smooth ; with six unequal valves, longi- 
tudinally wrinkled, and very remote, nearly obsolete striae on 
the raised portions; aperture very large, extremely irregular on 
the edge, internally striate transversely ; operculum abruptly 
conical ; posterior valves with serrated external margins, and 
striated transversely; anterior valves with numerous, strong, 
transverse ribs, which are crossed by many fine, longitudinal 
striae, producing a decussated appearance, and with their inter- 
nal margins serrated. 
Fig. 11, 12, the operculum. 
Fig. 8 is an elongated, cylindrical variety, found on the 
Devonshire coast, by Dr. Leach. The species seems very 
variable in form. 
This is the largest species of Balanus found in our seas, and 
seems pretty widely diffused. Fig. 10 was found by W. C. 
Trevelyan, Esq., at Hartlepool, adhering to a specimen of 
Fusus antiquus. Fig. 9 was figured from a specimen in the 
British Museum, and dredged in the Frith of Forth, where it 
is not uncommon ; and I have lately procured some large and 
beautiful specimens from the Irish coast. 
6. Balanus Scoticus, pi. LIII, f. 1, 2, 3, and 22. 
Balanus Scoticus, Wood, Gen. Conch., p. 40, pi. 6, f. 3. 
Shell subconic ; surface divided into irregular, triangular 
compartments, obsoletely striated transversely ; aperture large ; 
operculum triangular ; anterior valves with strong, transverse 
striae ; posterior valves smooth, with greatly arcuated and sharp 
poi nts. 
Fig. 2, 3, the operculum. 
Found at Eyemouth, Frith of Forth, and at the mouth of 
the Tay, adhering to muscles, stones, &c. 
7. Balanus punctatus, pi. LIII, f. 5, 6, 13, 20. 
Balanus punctatus. First Ed., pi. 7, f- 5, 6, 13, 20; Mon- 
tagu, p. 8, pi. 1, f. 5; Fleming, Edin. Ency., p. 101 ; Brown, 
Ency. Brit., VI, p. 402. 
Shell subconic, with indistinct compartments ; generally with 
numerous, longitudinal, narrow ribs, and several transverse lines 
of growth; aperture wide, rather plain on the edge; operculum 
somewhat depressed, with numerous punctures ; front valves 
finely striated transversely; posterior valves obtuse at the point, 
with the front margins deeply indented. 
Fig. 5, 6, the operculum. 
Fig. 20, an elongated variety. 
Common on many of the British and Irish coasts, and is plen- 
tiful on the rocks between Kinghorn and Kirkcaldy, Fifeshire. 
2 H 
8. Balanus Cranchii, pi. LIII, f. 9, 10, 11, 12. 
Balanus Cranchii, First Ed., pi. 7, f* 9, 10, 11, 12; Leach, 
Ency. Brit. Sup., Cirripedes, pi. 57 ; Lepas Cranchii, Brown, 
Ency. Brit., VI, p. 403. 
Shell a depressed cone ; compartments indistinct ; sides 
rounded, smooth, with numerous, longitudinal, frequently in- 
terrupted striae; basal margin extremely uneven; aperture very 
small, somewhat pyriform, and smooth at the edges; operculum 
very large in proportion to the size of the aperture ; anterior 
valves with strong, transverse striae in front, and becoming 
arcuated posteriorly ; when separated, their internal margin is 
found to be strongly serrated ; posterior valves striated trans- 
versely, with greatly arcuated, sharp points; external surface 
of a reddish-purple, tinged with pale yellowish-bufiF, and with 
from two to three transverse purple zones. 
Fig. 11, 12, the operculum. 
Common at Tenby, and other parts on the coast of Wales. 
9. Balanus conoides, pi. LIV, f. 7. 
Balanus conoides, First Ed., pi. 6, f. 7 ; Lepas conoides, 
Donovan, I, pi. 30, f. 3; Montagu, p. 12; Fleming, Edin. 
Ency., VII, p. 101 ; Maton and Rackett, p. 24. 
Shell conic ; valves pointed at the apex ; compartments ob- 
scure, the three posterior ones larger than the others ; whole 
surface longitudinally striated, and slightly so transversely, pro- 
ducing a reticulated appearance, and of a pale reddish-purple 
colour; aperture very small. Diameter at the base about 
three-eighths of an inch. 
Found at Weymouth, by Mr. Bryer, attached to a specimen 
of Pentelasmis Icevis. 
This is probably a foreign species. 
10. Balanus Montagui, pi. LIII, f. 24, 25, 26. 
Acasta Montagui, First Ed., pi. 7, f. 24, 25, 26; Balanus 
spongeosus, Montagu, Sup., p. 2 ; Fleming, Edin. Ency., VII, 
p. 101. 
Shell ovate ; with six angulated compartments, their points 
extending considerably above the margin of the aperture ; 
three anterior divisions broader and not so long as the 
posterior ones; external surface wrinkled, and provided with 
numerous, spiniform processes; operculum four-valved; ante- 
rior pair with strong, regular, deep, but narrow ridges, crossed 
by longitudinal striae, producing a decussated aspect, internal 
margins deeply serrated ; posterior pair larger than the others, 
and with considerably arcuated, sharp points ; colour of a 
livid or chocolate-brown. Length half an inch ; breadth some- 
what less. 
Fig. 25, shell the natural size. 
Fig. 24, magnified. 
Fig. 26, the operculum. 
Found embedded in sponge, at Portland Reach, by the late 
Mr. Bryer, of Weymouth. 
11. Balanus spongicola, pi. LIII, f. 14, 15, 16. 
Balanus spongicola. First Ed., pi. 7, f. 6, 14, 15 ; Leach, 
MSS., p. 1. 
Shell cylindrical ; with unequal compartments, the elevated 
portion rising above the margin of the aperture, which is as 
wide as the base of the shell ; operculum with four valves ; the 
anterior ones with pretty strong, slightly oblique, transverse 
striae, and decussated by rather slender, waved, longitudinal 
striae ; posterior valves longitudinally striated, with considerably 
