THE CARNIVOROUS SLUGS OF SOUTH AFRICA. 199 



bending its body at various angles like the typical form of 

 A. gibbon si. 



Apera gibbon si gracilis n. suhsp. 



External Characters (PI. VII, fig. 6). — Animal even more 

 slender than the typical form of Apera gibbonsi, tapering 

 to a very acute angle at the hind end. Outer lip of the 

 respiratory opening not concealing so much of the inner lip 

 as in the other forms of A. gibbon si. Eeticulation of skin 

 coarse, as in the typical form ; dorsal grooves united for 6 

 mm. in front of the respiratory opening. 



Body rather sparsely mottled with brown, as in A. gib- 

 bon si, s.s. ; the patches of colour, however, are not concen- 

 trated on each side of the mid-dorsal area, but extend across 

 it, so that there is no median paler band. 



The following are the measurements of the only specimen 

 that has been found : 



Length . . 44 ram. Greatest height . 6 mm. 



Breadth in middle 6 ,, Distance of i-esp. 



Breadth at resp. opening from hind 



opening . . 4*5 „ end . . H „ 



Breadth of foot-sole 3 „ 



Internal Characters. — Shell (PI. XIII, fig. 43) rather 

 longer and narrower at the posterior end than in the other 

 forms of A. gibbonsi. Radula (PI. XIX, fig. 123; text- 

 fig. 3, c, p. 1 59) with fewer teeth than that of any of the other 

 forms; central tooth absent; first on each side extremely small ; 

 outer teeth larger than in the preceding forms ; cusps only 

 slightly curved^ not broadened or barbed; apophyses very 

 prominent ; formula : (19 -|- + 20) x 34. Anterior 

 aorta passing through loop of intestine; branches of pul- 

 monary veins not very numerous. Penis rather long and 

 twisted. Other characters agreeing with those of A. gib- 

 bonsi s.s. 



Habitat. — Equeefa, Natal (Burnup). 



