PLATE CXXII.
Fiq.
1. Glandular organs of Filograna implexa, Berkeley, from St. Andrews (1863). Unfortunately
the explanation has been lost. X 180.
2. Tip of branchia of Pomatocems triqueter, L. (spirit-preparation). X 40.
2 a. Operculum of the foregoing, from Lochmaddy, North Uist. Enlarged.
3. Operculum of Placastegus tridentatus, J. C. Fabricius. X 40.
3 a. Tip of a branchia (in spirit). X 60.
4. Operculum of Placostegus, AB., from Shetland, x 40.
4 a. Outline of tip of branchia in spirit. X 60.
5. Lateral view of Ditrypci arietina, O. F. Muller, dredged off North Unst, Shetland.
Enlarged.
6. Tip of a branchia (spirit). Enlarged.
6 a. Tube. Enlarged.
6 b. Tube with Caryophyllia attached, from St. Magnus Bay, Shetland.
7. Operculum and branchiae of a very young example of Spirorbis grdnulatus, L., from
St. Andrews, a, non-ciliated terminal process; b, pinnae; c, opercular disc;
e, central calcareous process (talon). X 200.
7 a. Tube and annelid in life, 1863, St. Andrews. Enlarged.
7 b. Branchial pinna and peritoneal contents of body of an adult in life. X 280,
7 c. Anterior region of an adult showing the anterior granular glands, a. X 40.
7 d. Ovum, x 280.
7 e. Group of ova from calcareous tube. Enlarged.
7/. Embryo in capsule. X 80.
7 g. Free embryos. X 80.
7 h: Eye-specks. X 280.
7 i. Operculum. X 40.
8. Operculum of Spirorbis, CD., Cliff, Scalloway. X 40.
9. Operculum of Spirorbis spirillum, L., from Guernsey, x 40.
9 a. Operculum of the same from Aberdeen. X 40.
9 b. Tip of branchia (spirit). X 60.
10. Operculum of Spirorbis borealis, Daudin. X 40.
10 a. Tip of branchia. X 60.
11. 11 a, 116. Portions of three massive tubes composed of firm mud and with varying
admixture of stones—resembling those of Pista cristata—from the “ Porcupine ”
Expedition of 1869, the first, No. 25, at 164 fathoms, the second off the Hebrides,
and the third off Valentia.
12. Operculum of Spirorbis militaris, Claparede. Enlarged.