30 Proceedings of the Boyal Physical Society. 



panded (as figured), the branchial pro- 

 cesses, of which there are only three pairs 

 posterior to the dorsal tentacles, seemed 

 larger and more branched than those in 

 Sars' figures, which are more like the ap- 

 pearance presented by the processes after 

 immersion in alcohol. 

 The specimens were about 2 cm. in length 

 when fully expanded. One of them (Plate 

 I., Fig. 4) had the right dorsal tentacle 

 and the branchial process in front of it in 

 a rudimentary condition, while those of 

 the left side were fully developed. 

 Opposite farm-house on Holy Isle, about 

 200 yards from shore, 10 to 20 fathoms ; 

 and in 10 fathoms, along the shore from 

 Port Lewis towards the Cordon. 



Tkitoniid^. 

 Tritonia lineata (Aid. and Han.). 



On Plumularia pinnata off the south-west 

 side of Holy Isle, 20 fathoms. 



POLYCERID^. 



Triopa claviger (MUlL). 



On La?ninaria, 20 fathoms, south-east of 



Holy Isle ; and 10 fathoms, off Lighthouse. 

 Polycera lessoni (D'Orb.). 



Off the south-west side of Holy Isle, 20 



fathoms. 

 Goniodoris castanea (Aid. and Han.). 



Off Whiting Bay, 25 fathoms. 



Explanation of the Plate. 



Fig. 1. Eolis molios, n. sp. 



Fig. 2. One of the branchial processes of Eolis molios — a, dark blue; b, 

 cadmium -yellow ; c, brown band. 



Fig. 3. Dental plates from the radula of Eolis molios. 



Fig. 4. Heroformosa (Loven), dorsal view of abnormal specimen. 



Fig. 5. Hero formosa (Loven). 



Fig. 6. Dental plates from the radula oi Hero formosa, seen from the side. 



