THE CARNIVOEOUS SLUGS OF SOUTH AFRICA. 193 



liead is not unlike that of Apera sexangula and A. 

 gibbon si rubella. On the other hand, in Streptaxis 

 funki Pfr. the head is even more strongly curved than in 

 Apera dimidia; and, as in the Testacellidas and E.hy- 

 tididie, I have found two spiral filaments encircling the 

 proximal portion of the tail, the distance separating adjacent 

 whorls in this species being about •00115 mm. 

 The embryology of Apera is unknown. 



DISTRIBUTION. 



The genus Apera is only known to inhabit the maritime 

 provinces of South Africa. One species — A. pur colli — 

 occurs on the slopes of Table Mountain close to Cape 'J'own; the 

 other forms have only been found in Natal and in the eastern 

 districts of the Cape Province. A. parva is at present 

 only known to occur near Grahamstown ; A. sexangula 

 extends from that neighbourhood as far east as Pieter- 

 maritzburg ; the various races of A. gibbon si are known 

 to inhabit an area stretching from Pot)doland to Zululand ; 

 while A. burn up i and A. dimidia have only been found 

 in Natal. 



The animals are usually found in the bush, either amongst 

 dead leaves or under stones or logs ; but none of the species 

 are at all common. Apera sexangula and A., gibbonsi 

 seem to be the least rare. Of the others only six examples of 

 A. dimidia, four of A. burnupi, two of A. purcelli, and 

 one of A. parva are known to have been collected. It is to 

 be hoped that South African naturalists will gather further 

 specimens of this interesting genus, which not improbably 

 contains more species than are at present known. 



THE DIFFERENTIAL CHARACTERS OF THE SPECIES 

 AND SUBSPECIES OF APERA. 



Apera gibbonsi {Binney) . 



Chlamy depliorus gibbonsi Binn., Bull. Mus. Comj). Zool. Har- 

 vard. 1879, vol. V, p. 331, pi. ii, figs. (/, h\ Binney, Ann. N. Y. Acad. 



