A HISTORY OF NORFOLK 



thin, calcareous border. Zooecia tubular, in 

 radiating lines, crowded, without any radiating 

 intervals. Yarmouth, on Sabellaria tubes 

 (Harmer). 



ENTOPROCTA 



25. Pedkellina cernua (Pallas). 



Colonies consisting of clusters of whitish 

 cup-shaped zooids, laterally compressed, sur- 

 mounted by a crown of tentacles, and attached 



by stout, tapering, spiny stalks to a creeping 

 stolon. The zooids, when disturbed, sway 

 themselves about with much vigour. Yar- 

 mouth, on Vesicularia (Harmer). 



26. Loxosoma phascolosomatum, Vogt. 



Resembling the preceding, but the zooids 

 are in groups of separate individuals, not con- 

 nected by a stolon. Tentacular crown placed 

 obliquely ; stalk long, smooth, flexible. On 

 tail end of Phascolosoma (P.). 



VIII. ECHINODERMA {Star-fishes, Sea-urchins, etc) 



Nomenclature : Bell, British Museum Catalogue, 1892. 



1. Asterias rubens, Linn. 



The common red cross-fish or * five-fingers.' 

 Cromer (Geldart). 



2. Solaster papposus (Fabr.), 



The red 'sun-star'; arms 12 to 15. 

 Cromer (P. ; Geldart). 



3. Ophiura albida, Forbes. 



The smaller 'sand-star.' Disc and arms 

 smooth, scaly. Inter-radial plates (on the 

 lower surface) shield-shaped, almost as broad 

 as long. Common under stones at Runton 

 (Geldart). 



4. Ophiopholis aculeata (Linn.). 



Upper surface of disc ornamented with 

 small, irregular plates, separated by tracts of 



minute blunt spines or granules. Upper plates 

 of the arms ovate, surrounded by small acces- 

 sory plates. Off Cromer, fairly common (P.). 



5. Ophiothrix fragilis (O. F. Muller). 



The common ' brittle-star.' Disc covered 

 with spines in the intervals between the long 

 triangular radial shields. Arms very flexible 

 with long spines. Yarmouth (Harmer). 



6. Echinus miliaris, Linn. 



The shallow-water urchin. Shell more or 

 less depressed above and distinctly pentangular. 

 Rimton (Geldart), Yarmouth (Harmer). 



7. Echinus esculentus, Linn. 



The edible urchin. Shell almost spherical. 

 Off-shore only, except after gales when it may 

 be cast ashore (Geldart). 



IX. TUNICATA {Sea-Squirts or Ascidians) 



1. Ascidiella virginea (O. F. MUller). 



Body irregularly quadrangular, compressed, 

 the two siphons forming the upper angles. 

 Test smooth, transparent, colourless, showing 

 the brilliant crimson and white colouration of 

 the skin beneath. Length about 2 inches. 

 Adherent by the base to stones or shells. Off 

 Yarmouth (P.). 



2. Ascidiella aspersa (O. F. MUller). 



Body ovate, compressed, nearly twice as 

 long as broad ; apertures near together, ter- 

 minal. Test semi-transparent, rough with 

 conical papillae, especially near the siphons. 

 Length, 2-3 inches. Adherent by the base 

 and part of the left side to stones, shells, and 

 Fucus, in shallow water. Off Cromer (P.). 



3. Cynthia {Microcosmus) claudicans, Sav. 



Body erect, irregularly conical or ellipsoidal, 

 the mouth terminal, the cloacal pore about the 

 middle of the dorsal side ; both apertures 4- 

 lipped, on pyramidal siphons. Test leathery, 

 opaque, brownish, wrinkled, beset with fine 



prominences which agglutinate sand particles. 

 Branchial folds 8 or 9 on each side. Off 

 Cromer (P.). 



4. Cynthia {Polycarpa) comata. Alder. 



Body globular, lying free in sand, to which 

 it binds itself by numerous long branched 

 adhesive threads. Apertures 4-lipped, on 

 quadrangular siphons, lying close together in 

 a groove which closes over them during re- 

 traction. Branchial folds 4 on each side. 

 Off Cromer (P.). 



In external appearance and habits this 

 species resembles Molgula {Eugyra) glutinans, 

 Moll., which is recorded from the Silver Pit, 

 and is distinguishable by the 6-lipped mouth 

 and the absence of branchial folds. 



5. Molgula ampulloides^ ■3S\. Beneden. 



Body barrel-shaped, i inch long ; apertures 

 terminal on short siphons, the mouth 6-lipped, 

 the cloaca 4-lipped. Inhabits fine sand, to 

 which the animal binds itself by fine adhesive 

 threads. Branchial folds, 6 pairs. Off Cromer 

 (P.). 



86 



