Fam. 3, Plate 34. 



EOLIS TRICOLOR, Forbes. 



E. ovato-oblonga, pallide flavida; brancliiis elliptico-oblongis, infiatis, albis, linea centrali violacea, 

 apicibus flavo-annulatis, in seriebus 13-14 digestis : tentaculis fulvis; lateribus pedis anterioribus 

 rotundatis. 



Eubranchus tricolor, Forbes, Mai. Mon. p. 5. 



Eolis violacea, Aid. and Hanc., in Ann. Nat. Hist. v. 13, p. 166. 



Hab. On corallines from deep water (15 to 20 fathoms). Ballaugh, Isle of Man, and coast of 

 Anglesea, Professor E. Forbes. Belfast Lough, W. Thompson, Esq. Cullercoats, Northumberland. 



Body above an inch long, ovate-oblong, rather broad, and not much produced behind, 

 of a pale buffish yellow, tinged on the head with orange or fawn-colour. Dorsal tentacles 

 fawn-coloured, long and rather stout, tapering to an obtuse point. Oral tentacles much 

 shorter and smaller, inserted into the upper surface of the lips, and faintly tinged with fawn 

 colour. BranchitB large, elliptical, inflated, pellucid, yellowish white with the central gland 

 linear and of a deep violet colour, fading off to brownish orange below : an opaque ring of 

 brilliant golden yellow encircles the apex. They are set in 13 or 14 transverse rows, leaving 

 only a small space uncovered on the centre of the back. There are 3 to 5 papillae in a row 

 on each side, those next the back large and inflated, diminishing towards the sides, and very 

 small near the foot. A few papillae run along the sides as far as the dorsal tentacles. Foot 

 rather broad, pellucid, terminating rather abruptly in a point not much behind the branchiae. 

 The front margin is grooved transversely and rounded at the sides. 



This delightful species was first discovered by Professor E. Forbes on the coast of the 

 Isle of Man, and published in his Malacologia Monensis, under the name of Eubranchus 

 tricolor. Subsequent observations, however, have shown that it really belongs to the genus 

 Eolis, and that the individual first observed had been in a young and imperfect state. We 

 met with a single specimen at Cullercoats, in October 1843, which, not recognizing its 

 identity with Eubranchus tricolor, we published under the name of E. violacea. Since then 

 we have had a specimen sent us from Belfast Lough, by Mr. Thompson, and Professor Forbes 

 procured several splendid specimens by dredging on the Anglesea coast, some of which he 

 has kindly presented to us. 



Mr. Forbes remarks, in his manuscript notes with which we have been favoured, that 

 this animal when teased rolls itself up into a ball ; a habit which we had not observed. 



The eyes may very readily be seen in good specimens. The auditory capsule contains 

 only a single otolite. 



Fig. 1, 2, 3. Eolis tricolor, different views. 

 4. Papillae more highly magnified. 



