204 HUGH WATSON. 



Reproductive System (PI. XXIII, fig. 146). — Her- 

 maphrodite gland composed of only about four follicles, Avhich 

 are relatively very large ; albumen gland in the specimen 

 examined extending to the left side of the body-cavity, 

 passing between some of the posterior buccal retractors ; 

 common duct rather short, curving twice to the right and 

 once to the left ; vagina rather narrow ; receptaculum seminis 

 further forward than in the other species; receptacular duct 

 broad and extremely short. Vas deferens not enlarged to 

 form an epiphallus ; penis straight, rather short, and slightly 

 swollen in the middle; penial retractor long and narrow. 



Habitat. — Near Fern Kloof, about three miles south of 

 G-rahamstown, Cape of Good Hope (in a stony place with 

 very little grass, at least 200 yards away from the bush ; 

 Farquhar). 



Type. — The type is in the Natal Museum, Pietermaritzburg. 



Affinities, etc. — The only example of this species at present 

 known Avas discovered by Mr. John Farquhar, of Grahams- 

 town, on October 12th, 1913. In many respects the slug 

 bears a close resemblance to Apera gibbonsi, and it might 

 easily be mistaken for a young specimen of that species. 

 Nevertheless, it diifers from all the forms which I have 

 included under A. gibbonsi in so many characters that 

 there can be very little doubt that it is specifically distinct. 

 The following are the features in which some of the most 

 important diif erences occur : the size ; the number of the 

 radial and sub-lateral grooves ; the distance between the 

 cerebral ganglia ; the size of the teeth towards the edges of 

 the radula, and the width of the bases of all the teeth ; the 

 position of the origin of the buccal retractors ; the stomach ; 

 the course of the intestine ; the division of the arteries to 

 both portions of the liver ; the hermaphrodite gland ; and the 

 length of the receptacular duct and of the penial retractor, 

 these last features being perhaps the most striking of all. 



Apera dimidia n. sp. 

 External Characters (PI. YII, figs. 7-9; PL VIII, figs. 20, 



