1. I. e l eg a n s , Leuck. Rose-coloured, freckled, the processes orange-yellow; anterior filaments 2;
lateral filaments numerous, irregular, the posterior ones obtuse, lobular ; dorsal filaments
5,—3 on the median line, and 2 sub-lateral;, branchial plumes 18 (the anterior and posterior
ones bifid) ; foot margined with yellow. Length l j inch. PL 27, figs. 1—4.
2. I. Leachii, A. and H. White; filaments very long; anterior 4,lateral 6 on each side, the posterior
ones bifid; dorsal filaments numerous, in 3 or 5 rows; branchial plumes 11 (the anterior
one bifid). Length 1 inch. PL 27, fig. 5.
t Section 2. Centre of the back without filaments.
Lingual spines next the centre large, recurved and strongly denticulated; lateral spines
much hooked. Spinous collar incomplete, hilohed.
3. I. a s pe r sa , A. and H. Reddish or yellowish, freckled with orange and reddish-brown ; anterior
filaments 4 (2 close to the base of each tentacle) of equal length, long ; lateral filaments
short, 2 or 3 on each side near the branchiae ; branchial plumes 10 (the anterior and posterior
ones bifid), short, equal, forming a circle. Length 5 inch. PL 26, and Appendix (12), p. iv.
4. I. iNÆQUALis, For. Gray, speckled with yellow and brown ; anterior filaments 4 (2 near the base of
each tentacle), unequal, the exterior ones longest ; lateral filaments short, 5 or 6 on each
side ; branchial plumes 9 (the anterior one bifid), slender, diminishing posteriorly. Length
1 inch. Appendix (13), p. v.
5. I. p u l c h e l l a , A. and H. Freckled with pale lilac; tentacles sub-clavate; anterior filaments 4,
set on an expanded palliai ridge ; lateral filaments 5 or 6 on each side, the last large and
bifid; branchial plumes 11 (the anterior one bifid), rather small, diminishing posteriorly.
Length ^ inch. Appendix (14), p. v.
6. I. q u a d r ic o r n is , Mont. Mottled brown and white; anterior filaments 2 (1 near the base of
each tentacle;, long ; lateral filaments small, obscure ; branchial plumes 8 or 9. Length
§ inch. Appendix (15), p. v.
Fam. 2. T RITONIADiE . Branchiae plumose or tufted, set along the sides of the back. Liver
entire, central. Skin without spicula.
Genu s 9. TRITONIA, Cu vier.
Body sub-quadrilateral. Branchiae plumose or laminated, set on a pallial ridge along the
sides of the back. Tentacles 2, fasciculated, with plain sheaths. Veil digitated. Anus
lateral. Fam. 2, PL 1.
Tongue broad, with very numerous, simple or denticulated lateral spines: a tricuspid central spine,
and a plate on each side of it. Large corneous jaws.
\ T. H ombergii, Cuv. Purplish-brown or flesh-coloured, strongly tuberculated; veil bilobed, with
numerous small digitations; branchiae plumose, sub-foliaceous, forming a nearly continuous
line on each side. Length 3 to 6 inches. Pl. 2.
2. T. alba, A. and H. Transparent white with opaque white transverse markings, rather depressed,
smooth, or very faintly tuberculated; branchiae imperfectly bipinnate, 4 or 5 on each side,
with intermediate smaller ones, set on an expanded and waved pallial margin ; veil bilobed
with irregular digitations. Length § inch. Appendix (16), p. vi.
3. T. plebeia, Johns. Marbled with brown and yellowish above, subquadrate; veil entire, with 8
points; branchiae small, bipinnate, 5 or 6 on each side. Length 1 inch. Pl. 3.
4. T. lineata, A. and H. Transparent white, very slender, with a line of opaque white down each
side of the back; veil with 4 linear processes; branchiae small, pinnate, 5 on each side.
Length | inch. Pl. 4.
Gen u s 9 bis. SCYLLiEA, Linnaeus.
Body compressed, with large lobes on each side of the back, bearing the branchiae in
small tufts on their inner surface. Tentacles 2, laminated, with large sheaths. Fam. 2, Pl. 5.
Tongue broad, zoith numerous lateral spines and a central spine, (dl denticulated. Corneous
jaws.
1. S. pelagica, Linn. Cream-coloured, transparent, with 2 large branchial lobes on each side of the
back, and a posterior dorsal crest; tentacular sheaths trumpet-shaped, frilled posteriorly.
Length 1| inch. Appendix (17), p. vi.
Fam. 3. EoLTDIDJE. Branchiae papillose or fusiform, rarely ramose, set along the sides of the
back. Liver diffused. Skin without spicula.
Sub-Fam. Dendronotin^e. Tentacles 2, laminated, retractile within sheaths. Branchiae
branched or papillose. Veil with processes. Anus lateral.
Genus 10. LOMANOTUS, Verany.
Body subquadrilateral. Branchiae papillose or foliaceous, arranged in a nearly continuous
line on a pallial ridge on the sides of the back. Tentacles 2, with tight sheaths. (Fhimenis,
A. and H., included in Pl. 5 o f Fam. 2.) Appendix (18), p. vii.
Tongue broad, mth numerous denticulated spines: no central spine. Corneous jaws.
1. L. marmoratus, A. and H. Olivaceous, marbled with brown and white; tentacles with smooth sheaths;
branchiae forming a nearly continuous waved line of papillae on each side of the back.
Length 5 inch. Fam. 3, Pl. la (Eumenis marmorata).
2. L.flavidus, A. andH. Pale lemon-yellow; tentacles with tuberculated sheaths; branchiae papillose,
mostly short, with a few longer ones at regular intervals, all ringed with fawn-colour.
Length * inch. Pl. 41, figs. 6, 7.
Genus 11. DENDRONOTUS, Alder and H ancock.
Body compressed, without cloak. Branchiae ramose, set in single series on each side of
the back. Tentacles with branched sheaths. Veil branched. Fam. 3, Pl. 2.
Tongue rather narrow, with numerous lateral spines, and a large central spine, all denticulated.
Corneous jaws.
1. D. arborescens, Mull. Reddish, marbled with brown; veil much branched; branchiae 6 or 7 on
each side. Length 1 to 2 inches. Pl. 3.