A HISTORY OF NORFOLK 



V. GEPHYREA 

 22. Phascolosoma vulgare (Blainville). 



Body cylindrical ; skin yellowish, smooth, 

 tough, shining. Proboscis about half the length 

 of the body, and invaginable into the latter ; 

 its anterior swollen part provided with a 

 diffuse band of small brown booklets, and 

 with 1 6 circumoral tentacles. Length 5-6 

 inches. Burrows in sand. 



VI. CH.ETOGNATHA 

 23. Sagitta bipunctatay Quoy and Gaimard. 



Body cylindrical, elongated, transparent ; 

 provided with 2 pairs of lateral fins ; tail 

 fins small. Length f inch. Lives freely 

 floating in the sea. Mouth armed with lateral 

 hooks. 



VII. POLYZOA 



Animals of minute size, provided with a circlet of ciliated tentacles, and forming exten- 

 sive colonies, either reticulate, encrusting, or arborescent. The lower part of the body of 

 each individual (or zoo/W) has usually a horny or calcareous skin, which forms a box or tube 

 (called the zocecium), into which the delicate upper portion can be quickly withdrawn for 

 purposes of protection. In the Cheilostomes the ' mouth ' of this box can be closed by a 

 movable lid (the operculum) which in certain modified zooecia of the colony is converted into 

 a snapping beak (avicularium) or a long slender spine {vibraculum) for cleansing the colony. 



Nomenclature : Hincks, British Marine Polyzoa, 1880. 



I. CHEILOSTOMATA 



1 . Eucratea chelate (Linn.). , 



Colony composed of a creeping base (usually 

 lines of decumbent zooecia) and of delicate 

 branching shoots. Zooecia in single rows, 

 white, subcalcareous, expanding upwards ; 

 aperture oblique, margin unarmed ; often 

 bearing a short tubular appendage below the 

 aperture. Yarmouth, on Amathia and Vesi- 

 cularia (Harmer). 



2. Menipea ternata (Ell. and Sol.). 



Colony arborescent, forming delicate white 

 tufts with curling branches on the larger 

 Hydroids {Hydrallmania, Sertularia, etc.) to 

 which it binds itself by numerous tendrils. 

 Zooecia tapering below, united in sets of three ; 

 * aperture ' subterminal, oval, protected by an 

 overhanging fan-shaped spine, and 2 or 3 

 terminal spines. Large lateral avicularia. Off 

 Hasborough (P.). 



3. Scrupocellaria scruposa (Linn.). 



Colony arborescent, forming stiff bushy 

 tufts of a white colour. Zooecia in double 

 series. Aperture large, elliptical, with 2 

 slender spines only on each side above. 

 Under stones and on weeds, zoophytes, etc. 

 OfiF Hasborough (P.), Yarmouth (Harmer). 



4. Scrupocellaria scrupea, Busk. 



Like the preceding, but the aperture oval, 

 and protected by an overhanging opercular 

 plate, as well as by 3 spines on the outer 

 margin above, and i, or occasionally 2, on 

 the inner. OfiF Hasborough (P.). 



5. Scrupocellaria reptans (Linn.). 



Colony forming stiff ragged sprays. Mar- 

 ginal spines as in S. scrupea, but the opercular 



spine is branched and antler-like. Avicularia 

 and vibracula present in all three species. Not 

 yet recorded, but generally common between 

 tide-marks. 



6. Bicellaria ciliata (Linn.). 



Colonies pearly white, in delicate feathery 

 tufts. Zooecia biserial, alternate ; the ellipti- 

 cal aperture guarded by exceedingly long 

 marginal spines, viz. 4-7 above, 1 centrally 

 below, and i or 2 on the back. Yarmouth, 

 common (Harmer). 



7. Bugula plumosa (Pallas). 



Colony in tall feathery tufts, with fan-like 

 branches spirally arranged. Colour, when 

 alive, bright buff. Zooecia biserial. Aperture 

 large, with a single spine at the top. Avicu- 

 laria (' birds' heads ') very small. Recorded 

 off Hasborough and Lowestoft (P.), Yarmouth 

 (Harmer). 



8. Flustra foliacea (Linn.). 



The ' sea-mat.' Colony erect, in large flat 

 fronds of a brown colour, deeply divided. 

 Aperture with 2 marginal spines on each 

 side and often i at the top. Abundant off« 

 shore and thrown up in quantities on the 

 beaches (P.). 



9. Membranipora lacroixii, Audouin. 



Colony forming a thin gauze-like crust over 

 shells and stones. Zooecia oval or elongated ; 

 aperture oval, occupying the whole of the 

 front ; margin thickened ; spines usually I 

 pair above, rarely numerous (11), and then 

 very delicate and pointing inwards. Abun- 

 dant on dead Mytilus shells and other objects, 

 Yarmouth (Harmer). 



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