MOLLUSCA. 
123 
Serpulacea.] 
Section II. — Shells attached to extraneous bodies nearly 
their whole length. 
5. Serpula triquetra, pi. LV, f. 1, 5. 
Serpula triquetra, First Ed., pi. 2, f. 1, 5 ; Pennant, IV, p. 
146, pi. 91, f. 157; Donovan, pi. 95; Montagu, p. 511 ; Maton 
and Rackett, p. 244 ; Fleming, Edin. Ency., VII, p. 67- 
Tube adhering its whole length, strong, opaque, irregularly 
contorted ; sometimes nearly straight, or slightly flexous ; with 
transverse wrinkles, and provided with a central dorsal carina, 
which in some instances becomes nearly obsolete at the larger 
end of the tube ; in some specimens the ridge is elevated, and 
in others depressed ; spreading widely at the base ; aperture 
subtriangular ; colour yellowish-white, sometimes of a fine red, 
orange, citron, or rose-colour. 
Found on many of the British and Irish coasts, adhering to 
old shells, stones, &c. 
6. Serpula vermicularis, pi. LV, f. 2, 3. 
Serpula vermicularis, First Ed., pi. 2, f. 2, 3 ; Pennant, p. 
146, pi. 91, f- 158; Montagu, p. 509; Maton and Rackett, p. 
240; Brown, Ency. Edinensis, II, p. 556, pi. 55, f. 12; Ib., 
Ency. Brit., VI, p. 468. 
Tube strong, adhering its whole length, cylindrical, white, 
transversely wrinkled, contorted in various directions, tapering 
gradually to a fine point ; aperture circular. 
Common on most of the British and Irish coasts. 
7. Serpula serrulata, pi. LV, f. 8. 
Serpula serrulata. First Ed., pi. 2, f. 8 ; Fleming, Edin. 
Ency., VII, p. 67, ph 204, f. 8. 
Tube bluish-white, smooth, glossy, diaphanous, adhering, 
subtriangular, slightly contorted ; base spreading pretty widely, 
tapering rather abruptly to a fine point ; back with an elevated, 
thin, sharp ridge, finely but irregularly serrated, and equal in 
dimensions to the breadth of the tube ; aperture large, nearly 
orbicular, with the tooth-like termination of the carina project- 
ing over it. 
Discovered by Dr. Fleming, in deep water, adhering to 
stones, on the coast of Zetland ; and I found it plentiful in 
Rothesay Bay, in company with my friend James Smith, Esq., 
of Jordan Hill, near Glasgow, while on a dredging excursion. 
The shell is so transparent, that the animal can be distinctly 
seen through it ; and by the aid of a strong lens the pulsation 
may be observed. 
Genus 2 — Spirorbis — Lamarck. 
Shell consisting of a testaceous tube, spirally twisted into an 
orbicular form on a horizontal plane, depressed, and adhering 
below ; the aperture terminal, rounded, or angular. 
1. Spirorbis Nautiloides, pi. LVI, f. 45. 
Spiror'bis Nautiloides, First Ed., pi. 1, f. 45; Lamarck, V, p. 
359; Serpula spirorbis, Donovan, I, pi. 9, f« 1,2; Montagu, 
p. 498; Maton and Rackett, p. 241. 
Shell opaque, white, much depressed ; with three or four 
lateral volutions, rounded above, and slightly wrinkled trans- 
versely ; the central volution lower than the others, and 
forming an umbilicus ; base flat, and expanded ; aperture sub- 
triangular. 
Common on most of the British and Irish coasts, adhering 
to algce and other marine plants, as well as to stones and 
shells. 
A lusus of this shell is not unfrequent with an erect aperture, 
and one or two volutions turning a little spirally upwards. 
2. Spirorbis spirillum, pi. LVI, f. 41, 42, 53, 54. 
Spirorbis sphillum. First Ed., pi. 1, f. 41, 42, 53, 54; 
Lamarck, V, p. 359 ; Fleming, Edin. Ency., VII, p. 68 ; Ser- 
pula spirillum, Montagu, p. 499 ; Pulteney, Hutch. Dorset, p. 
52, pi. 19, f- 27 ; Maton and Rackett, p. 240. 
Shell subdepressed, subpellucid, glossy, white ; with two or 
three subcylindrical, slightly wrinkled, somewhat lateral volu- 
tions ; central volution lower than the others, forming an um- 
bilicus, and pervious in some instances ; aperture subtriangular, 
and not unfrequently turned upwards ; attached by the smaller 
end. Diameter not more than an eighth of an inch. 
Fig. 53, 54, var., Spirorbis sinistrosa, Montagu, p. 504. 
Sometimes the volutions wind spirally upon each other. 
Distinguished from S. Nautiloides by its glossy aspect, its 
more cylindrical form, and not spreading at the base. 
Generally found adhering to marine plants, corallines, and 
Crustacea, and not to stones. 
3. Spirorbis minutus, pi. LVI, f. 51. 
Spirorbis minutus. First Ed., pi. 1, f. 51 ; Fleming, Edin. 
Ency., VII, p. 68, pi. 205, f. 2 ; Serpula minuta, Montagu, p. 
505; Maton and Rackett, p. 241. 
Shell heteroclitical, depressed, yellowish-white ; with two or 
three lateral, transversely wrinkled volutions, and a dorsal 
carina. Diameter a quarter of a line. 
Found adhering to corallines, on the Devonshire and Nor- 
thumberland coasts. 
4. Spirorbis heterostrophus, pi. LVI, f. 55. 
Spirorbis heterostrophus. First Ed., pi. 1, f. 55; Fleming, 
Edin. Ency., VH, p. 68, pi. 205, f. 1 ; Serpula heterostropha, 
Montagu, p. 503 ; Maton and Rackett, p. 242. 
Shell strong, dull white ; consisting of two or three hetero- 
clitical volutions, with three lateral, spiral ridges, crossed by 
strong wrinkles ; base flat, somewhat spreading ; aperture orbi- 
cular. Diameter not a line. 
Found adhering to oysters and other shells, and to algcB, on 
many of the British and Irish coasts. 
5. Spirorbis heterocliticus, pi. LVI, f. 57. 
Spirorbis heterocliticus. First Ed., pi. 1, f. 57. 
Shell nearly cylindrical, thick, white, opaque, smooth ; with 
four volutions, the outer one very large, internal ones small, 
forming a large and deep umbilicus ; aperture nearly orbicular, 
and placed below tbe margin of the outer volution. Diameter 
one-tenth of an inch. 
Found by my late friend General Bingham, adhering to the 
roots of algce, at Dunbar. 
6. Spirorbis granulatus, pi. LVI, f. 47. 
Spirorbis granulatus. First Ed., pi. 1, f. 47; Fleming, Edin. 
Ency., VH, p. 68 ; Serpula granulata, Montagu, p. 500 ; 
Donovan, HI, pi. 100. 
Shell subdepressed, white, opaque; with two volutions, deeply 
grooved spirally, and transversely wrinkled, more strongly so in 
the furrows, umbilicated; aperture orbicular, with an annular 
tip. Diameter an eighth of an inch. 
