THE CARNIVOROUS SLUGS OF SOUTH AFRICA. 243 



than in most genera of the Oleacinidffi excepting Stre- 

 belia, but I have already shown that this is what we niiglit 

 expect in a genus with a degenerate shell. The other female 

 organs seem to be identical. The penis often ends in a caecal 

 diverticulum in the Oleacinidfe, which, however, is quite 

 short in Poiretia, and absent in Euglandina, Salasi- 

 ella, Streptostyla, and Strebelia. In Testacella we 

 frequently find a vestige of this diverticulum, especially in 

 T. haliotidea DraiJ. In the Oleacinidse an epiphallus 

 is usuall}^, though not invariably, inserted between the penis 

 and the attachment of the penial retractor ; this is also 

 the case in Testacella haliotidea, and sometimes in T. 

 maugei (PI. XXIV, fig. 159). Pfeft'er has shown that in 

 Euglandina liebnianni (Pfr.) the retractor springs from 

 the apex of a flagellum, exactly as it does in Testacella 

 haliotidea, and the same author has demonstrated that the 

 internal structure of the penis of Euglandina is not 

 unlike that of Testacella.^ Indeed, the similarity between 

 Testacella and the Oleacinidfe seems to me to be even 

 closer than the similarity between Apera and the Rhyti- 

 d i d 83 . 



The fact that the heart in Testacella is on the right side 

 of the kidney, with the auricle directly behind the ventricle, 

 affords further evidence in favour of this view, as will be seen 

 from the accompanying diagram. The usual position of the 

 heart in Hyalinia, Rh^^tida, and similar genera, is shown 

 in text-fig. 6, A — drawn from a specimen of Hyalinia 

 d rap am audi [Beck). In Daudebardia, according to 

 Plate, the heart is turned slightly to the right as shown in 

 diagram B; but it will be seen that the auricle is still in front 

 of the ventricle, and the kidney is still mainly on the right 

 side of the heart, though the shell no longer extends far 

 beyond these organs. In Apera the heart has rotated 

 further in the same direction and is not protected by the 

 shell (diagram c) ; the auricle has now come to lie further 

 back than the ventricle, and the kidney is behind and to the 

 ' • Jahrb. d. Deiitsch. Mai. Gesell.,' 1878, vol. v, p. 81. 



