382 On two rare British Nudibranchs. 
length when expanded. This is only half the length of 
Mr. Hunt’s specimen. Colour a purplish-rose, very similar 
to the Delesserva on which it lived. ‘Too much stress should 
not be laid on this point, however, since Mr. Hunt’s example, 
although apparently found on the same weed *, was olive in 
colour. The mid-dorsal and lateral lines of the upper surface 
darker. The epidermis of the upper surface is of a bluish- 
green hue, as Gosse has already noticed (loc. cit. p. 317). 
On the sheaths of the rhinophores are scattered bluish-white 
spots; semilunar markings of the same kind occurred at the 
base of the pleuropodial lobes (compare ‘l’rinchese’s figure of 
Govia rubra). Body widest behind the head, gradually 
tapering posteriorly. Head with an oral veil bearing four 
papille on each side, the second anterior one being the 
largest. These papilla were constantly changing their shape 
during life, as Gosse and Trinchese have recorded. Rhino- 
phoral sheaths erect, cylindrical, the margin subdivided into 
about ten rounded projections. ‘This agrees closely with the 
figure and description of the sheaths of Govia viridis. 'Those 
of G. rubra, on the other hand, have plain margins. Rhino- 
phores with a rounded, bulbous, laminated base, terminating 
above in a smooth columnar tip. Pleuropodium produced 
into four lobes on the right and five on the left, the fifth 
being rudimentary. The first pair of lobes are opposite, the 
rest gradually becoming alternate, as in Trinchese’s figure of 
Govia rubra. Each lobe is concave externally and is com- 
posed of seven papilla, one being dorsal and median, three 
anterior, and three posterior. The foot is rounded anteriorly, 
posteriorly it ends in a slightly bifid tail, as in Govéa (Trin- 
chese, loc. cit. p. 183 and my fig. 1). The anal papilla very 
small, cylindrical, situated halfway between the first and 
second lobes of the right side. Genital opening near dorsal 
surface between the rhinophore and the first dorsal lobe of 
the right side. 
In the appended table I have compared the different speci- 
mens of Hancockia and Govia. Although they all agree in 
main points, no two individuals do so in detail. 
* Gosse, loc, cit. p. 316, note. 
