Eolidia Embletbni. 



379 



Eolfdia Embletbm, of the natural size; 

 b, the same magnified ; c, a view of the 

 ventral surface ; d, a few of the bran- 

 chiae, magnified. 



white colour, with scarlet bran- 

 chiae tipped with white. Mouth 

 terminal, subinferior, wide. Ten- 

 tacula four, nearly equal, conical, 

 rather long, white : the anterior 

 marginal, the dorsal annulated. 

 Eyes minute, black, one at the 

 base of each dorsal tentaculum ; 

 and before these organs there is 

 a dusky spot, produced by the 

 opacity of the oral apparatus, 

 which consists of a pair of large 

 corneous jaws, and a filiform 

 spinous tongue. Branchiae nu- 

 merous, elliptic-oblong, round, 

 arranged in three series along 

 each side ; but the rows are in- 

 distinctly marked, and divided 

 at intervals into four companies 

 or patches; the first separated by a distinct interval from the 

 second, the others almost coalescing : they are of a fine scarlet 

 colour, with white apices, which appear to be perforate, and 

 from which a minute conical point can be extruded. Foot 

 smooth ; enlarged and rounded in front, where the corners 

 are produced into acute angular points. 



The transparency of the body permits us to observe that 

 the branchiae arise from a large vessel, or, perhaps, a mem- 

 brane, which runs in a wavy manner down each side, and is 

 somewhat branched. Each branchial filament consists of a 

 red central part, and a soft mucous skin which envelopes it. 

 The eye, when magnified, shows a transparent centre, like a 

 pupil, encircled with an opake black ring. 



I have dedicated this delicate and beautiful creature, the 

 pride of its family, to my friend Mr. Robert Embleton, pre- 

 sident of the Berwickshire Naturalists' Club. It is active ; 

 and, if disturbed when in motion, it contracts itself together 

 only for a moment, and then again resumes its walk ; or, 

 turning on its back, it glides along the surface of the water in 

 a reversed position. The structure of the branchiae seems to 

 ally it to the genus Tergipes [VII. 490.]. I have seen it 

 adhere to foreign bodies by means of these organs, the apices 

 of which seem to act as suckers. They are evidently cupped 

 or perforated; but the animal seems to have the power of 

 pushing out this depression, until the point assumes the 

 appearance of a small conical papilla. 

 Berwick upon Tweed. 



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