3o6 CHASTER AND HEATHCOTE : MOLLUSCA OF OBAN. 



One pure white specimen and one concentrically marked 

 with alternate bands of white and brown were taken off 

 Lismore. 

 * P. incomparabilis, Risso. {F. tcshe). [A.M.N.]. 



P. striatus, Miill. [A.M.N. ; rare, small, R.D.D. MS.]. 

 Dredged in Kerrera Sound and off Lismore. Two of the 

 specimens were remarkably fine It was generally found 

 attached by a byssus inside valves of Pecten and Modiola. 

 A specimen dredged off Lismore was adorned with con- 

 centric coloured bands similar to those of the P. tigrinus 

 noted above. 



P. pusio, L. Fairly common in Kerrera Sound and off 

 Maiden Island, generally attached to Pecten and Modiola 

 valves. One or two large specimens were found free and 

 not distorted. 



P. pes-lutrae var. septemradiatus, Miill. [Loch Etive, 

 R.D.D.]. Valves occurred sparingly everywhere. One 

 fresh dead specimen off the south end of Kerrera Island. 

 This species seems to be very rarely taken alive in the 

 dredge, and Mr. Brown suggests that it owes its escape to 

 its activity. 



P. opercularis, L. Very abundant at certain spots in Kerrera 

 Sound, the dredge frequently coming up filled almost 

 exclusively with this species. The specimens are small 

 and thin, often beautifully coloured — whitish, pink, yellow, 

 orange, red, and brown, the majority being red, generally 

 marbled in various shades. They are generally more or 

 less covered with Balani and SerpuIcB. Some curious 

 conical pink and white objects, generally furnished with 

 three diverging horns, were found adhering to the Pectefis. 

 The nature of these structures was a matter of doubt until 

 Canon Norman informed us that they were the opercula 

 of Serpulidia?i annelids. Brown records opercularis of the 

 same colours as those named from the Clyde district. 



J.C, vii., Jan. 1894. 



