Dr. Johnston on Scottish Mollusca. 53 



spreading, white. Foot ovate, white, undulated. Innume- 

 rable calcareous spicula enter into the composition of the 

 cloak and skin. 



This is readily distinguished from every variety of the pre- 

 ceding by the chaliced form which the branchiae assume when 

 displayed and by the smoothness of the cloak. I have not 

 seen Mulleins figure of D. obvelata, but the specific character 

 which Lamarck gives of it is very suitable to our species : — 

 "corpore ovali-oblongo, supra tuberculis parvis punctato; velo 

 marginali lato repando." 



3. D. bilamellata^ body ovate-depressed, the cloak rough, 

 with equal tubercles ; branchiae short, numerous, simply pec- 

 tinate, forming an uninterrupted circle. Plate II. fig. 8. 



Doris bilamellata, Linn. Syst. 1083. — D. fusca, Mull. Zool. Dan. Prod. 

 229- Zool. Dan. tab. 47. fig. 6 — 9. Lam. Anim. s. Vert. vi. i. 312. 

 D. verrucosa, Pen. Brit. Zool. iv. 82. pi. 23. fig. 2. male. Turt. Gmel. 

 iv. 77- Turt. Brit. Faun. 133. Fleming in Edin. Encyclop. xiv. 618. 

 Stew. Elem. i. 386. Flem. Brit. Anim. 28 2. — Tritonia verrucosa, Jame- 

 son in Wern. Mem. i. 556. 



Hab. On rocks near low-water mark. The sea near Aberdeen, Pennant. 

 Leith shore and Shetland Islands, Prof. Jameson. Coast of Berwick- 

 shire, not uncommon. 



Desc. Body about an inch long, oval, depressed, nearly 

 equal in breadth at both ends, which are rounded and plain. 

 Cloak mottled and clouded generally with brown of various 

 tints, rough or muricated with numerous nearly equal small 

 tubercles, the margin rather narrow. Dorsal tentacula conical, 

 smooth towards the base, closely imbricate on the upper half, 

 retractile within a simple cavity that sometimes appears like 

 an ocellated spot. Branchiae forming a circle of not less than 

 twelve simply pectinated short leaflets retractile within a de- 

 pression with an entire rim. Foot oval, white except where 

 stained by the interranea. As in the preceding species, the 

 cloak contains an immense number of calcareous spicula, of un- 

 equal sizes, and aggregated more particularly in the tubercles. 



This pretty species is subject to great variety in colour, and 

 I have seen one or two individuals which were entirely white. 

 It agrees so well with Linnaeus's description of D. bilamellata 

 that I have not hesitated to adopt his name ; and the figure 

 of Pennant is sufficient to enable anv one conversant with the 



