440 THE OPISTHOBRANCHIATE 



opportunities of investigating this question, and are convinced of 

 tlie distinctness of the species rufibranchialis and Landshurgii. 



31. CoRYPHELLA GRACILIS, AM. and Ranc. 



Two individuals, agreeing with Alder and Hancock's description 

 of this species, have been taken this year. One small specimen 

 was dredged on May 13th in the Sound between the Duke Eock 

 and Jennycliff, and another individual was obtained with the bottom 

 tow-net in Cawsand Bay, July 7th. This latter specimen was kept 

 alive for several weeks, and some time after its capture it was noticed 

 that the hepatic caeca were of a ginger-yellow colour, like the ori- 

 ginal example of Alder and Hancock. I believe, however, that the 

 colour was more reddish at the time of capture, and that it faded 

 under the conditions of its captivity. 



I was very much surprised to find that this individual responded 

 to shadows as stimuli for the erection of its cerata, unlike any other 

 nematocyst- bearing ^olid with which I have experimented. The 

 reaction was like that exhibited in Hermaea bifida (supra), although 

 not quite so rapid and complete. The eyes are conspicuous in this 

 species, and relatively larger than in other Solids which do not re- 

 spond to this stimulus. 



The opaque white spots at the tips of the cerata were not very 

 regularly distributed : they were mostly in the form of semicircular 

 patches on their anterior faces, as in Facelina coronata and Drum- 

 mondii. 



32. ■'^CoRYPHELLA Landsburgii, Aid. and Hanc. 



Another individual of this species, half an inch in length and of 

 an extremely slender and attenuated form, was trawled on the 25th 

 September this year by Mr. Cunningham among Hydroids {Ohelia 

 geniculata on Laminaria, Sertularella Gayi, and a little Antennularia) 

 near the Duke Rock. In colour and markings it was quite normal 

 and very transparent. 



Sub-family 5. — FAVORiNiNiE. 

 23. Favorinus, Gray. 



33. Favorinus albus, Aid. and Hanc. 



Two individuals were found together on the under surface of a 

 large flat stone at the east end of Drake's Island, low water, spring 

 tide, November 22nd, 1889. On the same stone was the spawn of 

 some Nudibranch (probably Polycera quadrilineata) , in five or six 

 circular ribbon-like patches ; upon this spawn in captivity the 



