468 Mr. C. Collingwood on Nudihranchiate Mollusca. 



a careful coloured drawing of it, which kept nie up till a late horn- 

 in the morning — intending, in case it died in the night, at all 

 events to have ]\Ir. Alder's opinion on the matter. Altogether 

 it was six hours under observation, during which time the ten- 

 tacles w^ere as I have described them. The first glance bestowed 

 upon it in the morning, however, dispelled the illusion ; for it 

 was crawling actively about in the vessel in which I had placed 

 it — its tentacles no longer short and corrugated, but long and 

 smooth, agreeing exactly with the description given by IMessrs. 

 Alder and Hancock, and the oral now exceeding the dorsal ten- 

 tacles in length. It is probable that the strong light thrown 

 upon it for examination with a low power of the microscope had 

 produced the retraction of the tentacles which had so altered its 

 appearance ; and although I several times removed it for awhile 

 from the light, it seemed to require some hours of darkness to 

 restore it to its natural form. Another peculiarity of form of this 

 specimen, and which I have not observed in any other EoUs, was 

 that the postei'ior end of the body suddenly narrowed behind 

 the last papillje, and bore superiorly two or three small but very 

 distinct and transparent papular elevations. 



It was placed in the aquarium, where it lived a few days, after 

 which it appeared to melt away ; the papillae fell oiF, and their 

 rich-red colouring matter, imbibed by a multitude of eel-like 

 creatures swarming about the mollusk, gave them all a similar 

 tint. Its length w^as four-tenths of an inch. 



Eolis concinna. — The only locality recorded for this small 

 species by IMessrs. Alder and Hancock is Whitley, Northum- 

 berland. To this I can add the Egremont shore, where, in 

 February last, I found two specimens upon fronds of Laomedea 

 gelatinosa, in company with other small species of Nudibranchs. 

 I did not see their spawn, which by Mr. Alder's specimens w^as 

 deposited out of the usual spiral form. They were about one- 

 fifth of an inch long. 



Eolis aurantiaca. — We have here a variety of this species, 

 found upon the Tvbularia growing upon the pontoons of the 

 landing-stage in company with Dendronotiis, Data coronata, 

 Eolis coronata, and papulosa, &c. The individuals taken in that 

 locality were short and thick, the papillse few and club-shaped, 

 and very easily broken off. Altogether they were the least 

 graceful Eolids which I have met with ; and although they ap- 

 peared to agree rather with Alder and Hancock's Eolis auran- 

 tiaca than with any other, still there was a difficulty — viz. that 

 they were pale specimens, entirely free from any orange colour. 

 I therefore forwarded some to Mr. Alder, who kindly wrote me 

 word that he believed them to be specimens of Eolis aurantiaca, 

 which they had found to vary considerably in colour since it 



