1903.] FROM EAST AFRICA AND ZANZIBAR. 375 



and 4" 5 broad. The dorsal surface was covered with reddish- 

 brown granulations, each surrounded by a grey or white I'ing, and 

 there were also in one specimen eight chocolate-coloured blotches 

 with white edges, four around the rhinophores and four in front 

 of the branchial pocket. The rhinophores were dark brown, the 

 gills grey, with a thin white line down each pinna. In the 

 smaller specimen (which appeared to be indubitably the same 

 species) there were no blotches and the gills were drab-colovired. 

 The blotches have also vanished from the alcoholic specimen, 

 which is of a dull reddish brown, darker in places owing to 

 aggregations of minute black spots. The under surface is of a 

 vmiform reddish brown. The texture is hard and rough, as usual 

 in the genus. The visceral mass is 3"2 centimetres high and 

 arched, but the mantle-margin is low and flat. This margin is. 

 exceedingly ample, measuring as much as 2"6 centimetres at the 

 sides, 2"2 behind the tail, and 1*7 before the head, although the 

 dimensions of the whole alcoholic specimen are only 6'9 by 6*1 . 

 The small foot is grooved and notched in front but not very 

 deeply. The rhinophore-pocket is slightly raised and crenulate. 

 The branchial pocket is entirely closed by six lobes. The anterior 

 and posterior lobes are broad flaps, and considerably larger than 

 those at the side, which are nari'ow and pointed. The gills are six, 

 tripinnate, not very large or very sensitive. There is no labial 

 armature. The radula was injured, but was clearly large and 

 composed of closely-packed simply hamate teeth. Perhaps the 

 formula may have been abovit 50x100.0.100. The innermost 

 teeth are smaller than the rest ; the outermost irregular in shape. 

 The stomach is large and free, thin, and only partly laminated. 

 The large double blood-gland is partly anterior and partly pos- 

 terior to the central nervous system. There is a genital armature 

 of discs and hooks as described by Bergh. 



19. Plattdoris scabra (Ouv.). 



Three specimens from Wasin. 



The alcoholic specimens have preserved the hue of the living 

 animal unusually well. The ground-colour is yellowish white, 

 with irregular violet mottlings of varying intensity formed mostly 

 by minute rings of the same colour with yellowish- white centres 

 or by spots. The underside is a clear yellowish white, with no 

 markings except at the sides of the foot which are mottled like 

 the back. The branchise are light yellow with gi'ey axes ; the 

 rhinophores, buccal mass, and viscera all light yellow, and there 

 is a thin rim of the same colour round the pockets of the rhino- 

 phores and branchiae. 



The largest speeimen is 9 centimetres long, 5*2 broad, and 2'2 

 high. The visceral mass is somewhat arched and the wide mantle- 

 margin undulated. It is 1*9 centimetres broad at the sides, 1*5 in 

 front of the head, and 1*2 behind the tail. The foot is small and 

 narrow ; it is grooved and notched in front but not very deeply, 

 and the upper lip is thick. The branchial pocket has six lobes, as 

 in Platydoris eurychlamys, the anterior and posterior lobes being 



