172 Transactions of the Royal Society of South Africa. 



slightly immature specimens found under leaves in the bush at Kosi Bay, 

 Zululand, by F. Toppin (Collector for the Natal Museum), and sent to 

 England in spirit by H. C. Burnup, to whom the writer is much indebted. 



External features of the animal. — The dermal grooves are similar to those 

 of the next species (PI. VII, figs. 2, 7), there being, in addition to the usual 

 dorsal and oblique lateral grooves on the neck and the vertical grooves on 

 the front of the head, a conspicuous peripodial groove on each side, the two 

 grooves meeting above a well-marked caudal mucous pore. The hind end 

 of the foot is somewhat truncate in form, and there is no keel. 



The dark bands on the sides of the neck seem to be absent, but irregular 

 streaks and spots of dark pigment are scattered over the translucent skin 

 of the mantle and visceral hump, and a larger grey patch occurs just behind 

 the respiratory opening. 



The left body-lobe is divided into two widely separated portions, as 

 shown in PI. VI, fig. 1. 



Pallial organs. — The respiratory and excretory organs are shown in 

 the same figure, from which it will be seen that a few small veins occur on 

 the roof of the lung in addition to the main pulmonary vein, which is very 

 prominent. The kidney is long and narrow, with a recurved ureter arising 

 from its front end. 



Pedal gland. — This organ is embedded in the muscles of the foot. The 

 glandular tissue completely surrounds the central duct, which is crescentic 

 in transverse section. The gland is simple in structure, and seems to bear 

 some resemblance to that of the Dorcasiinae, as will be seen from PI. VI, 

 fig- 2. 



Central nervous system. — The nervous system closely resembles that of 

 the next species (PI. VII, fig. 3). The nerve-ring may either surround the 

 buccal-mass, or be situated just behind it, as in the specimen shown in 

 PL VI, fig. 4. Each cerebral ganglion has a well-marked anterior lobe. 

 The visceral ganglia are rather closely approximated, but not completely 

 united. The buccal ganglia are situated immediately behind the anterior 

 end of the oesophagus, and are oval in form, being joined by a commissure 

 about 0-5 mm. in length. 



Digestive system. — The jaw (PI. VI, fig. 3) is brown, 1-6 mm. long, and 

 transversely striated, the striae being inconspicuous, but a little better 

 developed than in Ps. cressyi Conn. 



The radula (text-fig. 19) measures 3x1-25 mm., when flattened out. 

 The central teeth are narrow, with single short cusps, but they are not 

 quite so narrow and degenerate as in the next species. The other teeth are 

 also broader and relatively shorter than in Ps. cressyi, and the first five on 

 each side are almost unicuspid, the ectocone being reduced to a narrow 

 flange on the outer side of the base of the conical mesocone. They thus 



