MOLLUSC A OF PLYMOUTH SOUND. 193 



20. Cavolina, Cuvier. 



30. 0. OLivACEAj A. and H. 



One specimen, dredged on May 11th, one mile south of the Mew- 

 stone. It was three eighths of an inch in length. The two pairs 

 of lateral streaks of rose colour on the head were very well marked. 



31. C. Farrani, a. and H. 



Two examples of this species were obtained at different times 

 during October, 1888, from the Cattewater. The dorsal tentacles 

 were short and rather thick. The oral tentacles were thicker and 

 longer than the dorsal, entirely orange in colour, and constricted at 

 the bases. One of them deposited some spawn, attached by the edge 

 and coiled two and a half times. 



On November 1st a number of Eolids were found on the blades 

 of some Laminaria saccharina from the Cattewater (under Queen 

 Anne's Battery), on which extensive stocks of Ohelia genicidata \Yere 

 growing. I described aud classified them at the time as follows : 



'' A. Gavolina Farrani. — White in colour, with orange-tipped 

 branchias. Seven or eight. 



" B. Gavolina, sp. — Length half an inch or more. Dorsal tenta- 

 cles rather longer than the oral but more slender. Body transparent, 

 whitish, marlced on the hack with large patches of orange red. Bi'an- 

 chial papilla3 inflated or elliptical ; in six, seven, or eight rows, 

 three papillee on each side ; of olive-green colour, orange ai tips. 

 Dorsal and oral tentacles coloured like the branchiee. Large oval 

 patch of yellow pigment behind the dorsal tentacles. Back of head 

 olive brown, merging into orange red below (i. e. in front of the bases 

 of) the dorsal tentacles. 



" In the larger specimens the colours of the branchise and back were 

 much intensified, the branchiae being of a deep purplish black, and the 

 back being mottled with deep orange red. The upper large branchiee 

 had whitish, not orange, tips. The oral tentacles were almost entirely 

 orange in colour ; the dorsal tentacles were long and cylindrical. 

 Five or six specimens.^' 



The examples of FoUs Farrani which Mr. Murray obtained on the 

 coast of Elgin were mainly of a purplish or umber tint, and the 

 colour of the tips of the branchial papillee was " generally whitish, 

 witli only a slight tinge of orange " (see Alder and Hancock's Mono- 

 graph, Appendix, pp. xi, xii). M'Intosh also has obtained ''fine 

 purple varieties" at St. Andrews, and his figure shows the presence 

 of deep orange-red pigment (17, plate ii, fig. 13), therefore I thdnk 



NEW SERIES. — VOL, I, NO. II. 13 



