MARINE ZOOLOGY OF ARRAN. 273 



comb, are as bright as burnished gold. In the Terebellce, 

 inhabitants of mud, the numerous and long worm-like ten- 

 tacles present the appearance of so many separate Annelids 

 entwined around their common prey. The genus Eunice 

 occupies a tube composed of a substance not unlike thin horn, 

 or the slender quill of a bird. The spiral white spots, fre- 

 quently spread over tangle or other large sea-weeds, are 

 examples of Spirorbis. The sea-mouse, Aphrodita aculeata, 

 obtained with the dredge, will easily be recognized by the 

 metallic lustre of its long bristles, which, partially covering 

 the animal, give out the colours of the rainbow. Some of 

 the marine worms are remarkable from the enormous length 

 to which their thread-like bodies are extended. Another 

 class of widely-diffused beings, not yet sufficiently investi- 

 gated on the Arran shores, and which, like the Annelids, are 

 worthy of a more honourable name than is assigned to them 

 in popular language, are the Sea-slugs, known in scientific 

 phraseology as the Nudibranchiate mollusca. These are 

 within the reach of every observer ; for, at low water, they 

 may be seen reposing under loose stones, or adhering to Algce. 

 Some of the species, especially of the genus Eolis, are really 

 charming objects elegant in form and beauteous in colour. 

 They cannot be mistaken. Place a specimen in a tumbler of 

 sea- water, it will unfold itself, and its gills, differently situated 

 in different species, will be seen expanding into full operation 

 as the little creature pursues its journey round the sides of 

 the vessel. It enjoys the learned appellation of Nudibranch, 

 because its branchiae, or breathing organs, are naked, or ex- 

 terior to the body of the animal. The genera Doris, Eolis, 

 Goniodoris, Lomanotus, Polycera, and Triopa, have been 

 found in the bays of Brodick and Lamlash ; but, if an active 

 search be made, the number of ascertained species will doubt- 

 less be greatly augmented, and the labourers in this depart- 

 ment will be amply rewarded. Nor must we altogether 

 overlook, as among the more remarkable forms, the Acalepha, 

 to which the Medusae and other Jelly-fish or Sea-nettles be- 



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