194 EEPORT ON THE NUDIBRANOHIATE 



there can be little doubt that our specimens were varieties of the same 

 species, Gavolina Farrani. Compare also Mcintosh's Eolis Andrea- 

 jpolis (18), probably a variety of G. Farrani, not a distinct species. 



" 0. Cavolina, sp. — Same generally as B, but the tips of the 

 branchiae are of an opaque white, instead of orange, and very con- 

 spicuous. The patches of colour on the back are crimson rather 

 than orange, and the integument has the appearance of velvet. One 

 specimen.^' 



Probably also a variety of G. Farrani. 



" D. Gavolina, sp. — Half an inch in length. Body slender. Bran- 

 chiae numerous. Entirely white in colour. Two specimens." 



No doubt another variety of G. Farrani. 



" E. Gavolina, sp. — Half an inch in length. Body slender. En- 

 tirely orange in colour. Tentacles equal in size. Branchiae inflated, 

 in six or seven rows of three papillae on each side. Central gland 

 much sacculated. Papillte with specks of opaque orange ; no specks 

 on the tentacles. Eadula as figured and described by Alder and 

 Hancock for Eolis Farrani. One specimen." 



Certainly a variety of the same species. Compare also M'Intosh's 

 Eolis Rohertianse (18). 



All these Eolids were feeding upon Obelia geniculata, and were 

 obtained from the same blades of Laminaria. As they all agreed 

 so far as structure is concerned (except as to slight variations in the 

 length of the tentacles), there can be hardly any doubt that they 

 are members of the same species Gavolina Farrani, A. and H. ; and 

 in trying to estimate the value of colour in the Eolididse it is cer- 

 tainly very puzzling to find almost equal numbers of two very different 

 colour-varieties (A and B) of a species living under exactly the same 

 conditions. I am not quite sure yet of the reason for this dimorphism. 



With the above-described examples of Gavolina Farrani taken 

 from the Laminaria on November 1st there was another Eolid which 

 for convenience' sake I will describe here, although its structure 

 does not admit of its being placed in the same genus. 



32. Eolis? sp. 



Body half an inch in length. Foot produced at the corners 

 anteriorly. Dorsal tentacles wrinkled with regular annuli, not 

 laminated ; set considerably apart at their bases. Branchial papillae 

 in fourteen or fifteen rows, four papillae on each side ; papillee slender 

 in form. Oral tentacles longer than the dorsal. Colour of body 

 transparent white ; glands of branchiae yellowish. Opaque white 

 spots at tips of branchiee in the form not of complete rings but of 

 semilunar or crescentic patches on their anterior faces. Very cha- 



