104 Mr. Forbes 07i new British Mollusca. 



obtecto^ tentaculis carneis bast tuber culatis^ branchiis albis, 



pede albo, Lon. 1^ unc. 



This beautiful addition to our Fauna was found in July 

 last under a stone at low water at Devar Island, near Camp- 

 beltown, Argyleshire. In form it is more elongated' than any 

 other British species of its division. Its colouring is most 

 remarkable : the ground colour of the mantle is jet black, 

 dotted here and there with little round spots of the brightest 

 cobalt blue, and covered at regular distances by ovate pink 

 tubercles, which are larger around the roots of the large 

 white plume-like branchia (six in number), and also around 

 the bases of the tentacula. The tentacula are singular, on ac- 

 count of being planted as it were on the summit of a tuber- 

 cled pedicle, in shape resembling the stalk of a clove. This 

 pedicle is pink, the tentacula darker, rather inclined to brown- 

 ish ; some of the tubercles, especially those near the anus, 

 are lobed. The foot is pinkish white, its anterior margins 

 not produced into tentacula. The creature is rather sluggish 

 in its motions, but noble in its aspect : its ornate mantle, its 

 sceptre-like tentacula, and plume of snowy branchiae like 

 ostrich feathers, dignifying it much above its British bre- 

 thren. 



III. Nov, Gen. Goniodoris. Forbes, 



Body prismatic : mantle marginally reflected, abbreviated pos- 

 teriorly : oral veil forming two sustentacula : posterior ex- 

 tremity acute, caudiform : branchia dorsal, unprotected. 

 Having to describe a new prismatic Doris, I avail myself 

 of this opportunity to characterize the above genus; the 

 establishment of which I consider absolutely necessary for 

 the following reasons. The dorso-branchiated Nudibran- 

 chia form a most natural family, consisting of the genera 

 Doris, Goniodoris, Polycera, (Thecacera}), and Euploca- 

 mus, which last genus conducts us to the next family, the 

 Tritoniacece, On reviewing their characters, we find their 

 generic distinctions to depend, 1st, on the form of the body; 

 2nd, on the form of the mantle ; 3rd, on the sustentacula ; 

 4th, on the posterior termination ; and 5th, on the position 

 and protection of the breathing organs, which also afford 



