MARINE ZOOLOGY 



10. Membranipora monostachys. Busk. 

 Colony incrusting, branching and reticu- 

 lated. Zooecia ovate, slightly narrowed be- 

 low ; aperture oval, occupying two-thirds of 

 the front ; margins thin, bearing a central 

 spine below, and sometimes a pair near the 

 top; or armed with numerous (i8) delicate 

 spines pointing inwards. Yarmouth, on mus- 

 sel shells, etc., abundant (Harmer). 



The variety fossaria, forming friable sponge- 

 like masses on the stems of plants, occurs near 

 Yarmouth in ditches of brackish water a mile 

 from the sea (Wigham). 



11. Membranipora pilosa ijuinn.). 



Colonies in large flat incrusting sheets on 

 Fucus and other weeds, between tide-marks. 

 Aperture oval, surrounded by numerous mar- 

 ginal spines {4-12), which bend inwards; a 

 long horny spine usually present behind the 

 area. Cromer (Harmer), Hasborough (P.), 

 Yarmouth (Harmer). 



12. Cribrilina annulata (Fabr.). 



Colonies forming small circular reddish 

 crusts on Laminarla, shells or stones. Zocecia 

 ovate, convex ; the sides wrinkled. About 

 6 pairs of perforated centripetal furrows. The 

 raised calcareous bars between the furrows 

 represent the marginal spines of Membranipora 

 fused into a roof over the membranous aper- 

 ture. Orifice suborbicular, with a thickened 

 rim and 3 (or 4) terminal spines. Inside a 

 mussel-shell off Yarmouth (P.). 



13. Schizoporella linearis (Hassall). 



Colony incrusting, rose-coloured. Zooecia 

 entirely calcareous, rhomboidal, in regular 

 rows, separated by raised lines ; orifice round, 

 with a pointed notch below, and 2-4 spines 

 above. Avicularia minute, elevated, usually 

 one on each side behind the orifice. On 

 Sabellaria tubes, Yarmouth (Harmer). 



14. Mucronella peachii (Johnst.). 



Colonies incrusting, calcareous, large, flat, of 

 irregular outline ; on Laminaria, shells, stones, 

 etc. Zocecia ovate, globose, notched around 

 the margin (a relic of the gaps between ances- 

 tral roofing spines, cf. Cribrilina). Orifice 

 subquadrangular, mucronate, with 6 spines or 

 denticles. No avicularia. Off Cromer and 

 Hasborough (P.). 



15. Lepra Ha pertusa (Esper). 



Colonies calcareous, circular, incrusting, 

 orange-coloured, with a glistening lustre. 

 Zocecia large, ovate, tumid, closely punctured ; 

 orifice circular. Avicularia rare; small, oval, 

 placed on one side near the orifice. On shells, 

 stones, etc. Off Hasborough (P.). 



16. Cellepora costaziiy Andouin. 



Colonies minute, calcareous, incrusting ; 

 on stems of sertularian hydroids and algae. 

 Zooecia crowded, ovato-cylindrical ; orifice 

 terminal, with a prominent knob on each side 

 bearing a minute avicularium. Off Has- 

 borough (P.). 



II. CTENOSTOMATA 



17. Alcyonidium gelatinosum, Linn. 

 Colonies erect, gelatinous, smooth, lobed 



and branched, yellowish in colour. Height 

 usually 3 to 18 inches. Off Yarmouth (P.). 



18. Alcyonidium mytili, Daly ell. 



Colonies incrusting, fleshy, dingy white, 

 the surface finely papillated and showing the 

 hexagonal boundaries of the zooecia. Com- 

 mon on shells, etc., Yarmouth (Harmer). 



19. Vesicularia spinosa (Linn.). 



Colonies arborescent, horny, very delicate ; 

 the main stems zigzagged, the branches dicho- 

 tomously branched, bearing oval transparent 

 zocecia at intervals. Height 4-12 inches. 

 On stones, oyster-shells, etc. Off Yarmouth, 

 common (Harmer). 



20. Amathia lendigera (Linn.). 



Colonies arborescent, in tangled masses on 

 fibrous algae and zoophytes. Zooecia cylin- 

 drical, disposed in small groups immediately 

 below the forks of the branches, each group 

 consisting of 4-8 pairs arranged in two con- 

 tiguous parallel rows. Tentacles 8. Yar- 

 mouth (Harmer). 



2 1 . Bowerbankia imbricata (Adams), var. dema. 

 Colonies (in the variety) consisting of large 



cylindrical transparent zooecia, disposed in 

 groups along a creeping stolon. Tentacles 

 10. On Fluitra, Yarmouth (Harmer). 



22. Triticella flava, Dalyell. 



Zooecia laterally compressed, erect, ovate, 

 attached to a creeping stolon by short stalks, 

 on which they are movable. On backs of 

 crabs {Portunus holsatus), Yarmouth (Harmer). 



III. CYCLOSTOMATA 



23. Crista aculeata, Hassall. 



Colonies in small white tufts, the branches 

 curling inwards. Zocecia tubular, calcareous, 

 in double series, many bearing a long spine 

 near the top ; the series are divided into seg- 

 ments by yellowish horny joints. Height 

 ^l inch. Yarmouth, on Flustra, Vesicularia 

 and Hydroids (Harmer). 



24. Diastopora patina (Lamarck). 



Colonies small (| inch diameter), white, 

 calcareous, discoid ; surrounded by a broad. 



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