Mr. Forbes on new British MoUusca. 103 



was not that species, but the Doris tuberculata of Cuvier, 

 and accordingly described it as such in the Zoological Jour- 

 nal and in his valuable paper on Scottish Mollusca in the first 

 volume of the Annals. During the last two years, however, 

 I have dredged on the Manx coast two specimens of a Doris 

 which may be considered as the true Argo, and as such is an 

 addition to the British Fauna. This Doris is of an oval form, 

 the largest 1 1 inch in length, by rather more than | broad. 

 It is of a most vivid orange-red colour with lighter specks 

 on the back. The mantle is covered with very minute papillae, 

 and round the base of each tentacle, which is formed as in 

 other Dorides, there is a circle of papillae somewhat larger 

 than those studding the back. The branchiae are ten in 

 number, bipinnate, bright red edged with blackish green. 

 The foot is smooth and red. It was dredged in about 20 

 fathoms water on the shell-bank off the coast of Ballaugh, 

 Isle of Man. In its motions it is extremely sluggish, but 

 from the beauty of its colouring is a most attractive spe- 

 cies. 



The original Doris Argo is represented in Bohadsch, " De 

 quibusdam Animalibus Marinis" tab. v. figs. 4 and 5. The 

 animal there figured was 3 inches and 5 lines long, but the 

 accompanying description well agrees with my specimens. 

 In the figure it seems smooth, and as such it has generally 

 been described, but from their minuteness the papillae might 

 have easily been overlooked. Bohadsch's description of the 

 colour of its back, " In parte prona seu dorso colore coccineo 

 splendet" (p. 66), is most appropriate. The origin of the 

 name "Argo" as applied to this species is singular. Bo- 

 hadsch, observing the summits of the tentacula to be speckled 

 with minute black specks, fancied them to be eyes, and ac- 

 cordingly bestowed on his animal the name of Argo or Argus, 

 as he said he could easily count a hundred or more of these 

 eyes. This speckled appearance is seen on the tentacula of 

 many Nudibranchia, and is merely a variation in the colour- 

 ing of the animal. 



II. Doris Maura. Nov. Sp. Forbes. Plate II. fig. 17. 

 D. elongata, dorso nigro cceruleo-niaculatOj tuberculis carneis 



