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or organs of respiration. Let the shadow of your hand pass near 

 the side of a glass vessel, in which a living specimen is contained, 

 and instantly the head starts back into concealment ; but watch, 

 and in a few moments its brilliant coronet will reappear. The 

 Pectinaria resides in a house made of the finest sand cemented in 

 the form of a tapering tube ; and its gills, in shape like a minute 

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

 of mud, the numerous and long worm-like tentacles 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 frequently spread over tangle or other large 

 sea-weeds are examples of Spirorbis. The sea-mouse, Aphrodita 

 awdeata, 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 investigated 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 Alg<z. 

 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 branchice, 

 or breathing organs, are naked, or exterior to the body of the 

 animal. The genera Doris, Eolis, Goniodoris, 1/omanotus, Poly- 

 cera, 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 doubtless be greatly augmented, and the labourers in 

 this department 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 belong. 

 Some of the larger and coarser species are familiar to sea-bathers 

 by the stinging qualities of their tentacula. But there are other 

 species a? harmless as they are lovely. On a calm summer day, 



