222 Mr. W. E. Collinge o?i the 



O" 



Besclireibung : ' Dorsum finely sulcato-striate from head to 

 orifice. A row of small regular tubercles runs along medial 

 line from head to prominence'), die Seltenheit des Vorkom- 

 mens, die wohl in der gemeinsamen unterirdischen Lebens- 

 weise begriindet ist, und dergl. mehr." 



That Aj^era has affinities with the Testacellid^ there can 

 be little doubt, but there is a wide gap between it and either 

 Testacella or Daudehardia. 



In the generalized character of the generative organs 

 Apera resembles in some ways the genus Schi'zoglossa, but 

 until we have a more detailed account of the anatomy of this 

 last-named genus it will be difficult to rightly classify it. 

 There is a still wider gap between Apera and ScMzoglossa 

 than between Apera and either Testacella or Daudehardia. 

 Godwin-Austen (4, p. 8) has placed Schizoglossa with ^lea 

 and ParypJianta in a new subfamily Paryphantincej on the 

 following grounds : — " In the form of the buccal mass this 

 new subgenus [Schizoglossa) shows best the close relation- 

 ship which it has with Parypha^Ua, both in the rounded form 

 of the basal end and in the unification of the salivary glands, 

 neither of which characters are to be seen in Testacella 

 Jialiotidea which I have examined ... In the generative 

 organs we find this diffiirence, the vas deferens in Testa- 

 cella joins the male organ near the attachment of the retractor 

 muscle at the posterior end, whereas in Paryphanta and 

 ScMzoglossa it is peculiarly short and joins the male organ 

 very low down just above the generative aperture." 



Judging from Hedley's description and figure of the 

 generative organs of ScMzoglossa it would appear that we 

 have here a mollusk in which numerous modifications have 

 taken place. The absence of any receptaculum and the 

 generalized character and feeble development of the male 

 organs certainly make it difficult to rightly assign it to any 

 family of mollusks where these are predominant features. 

 There are not a few points in which it shows an affinity to 

 Apera, and through this genus to Testacella and Daudehardia ; 

 at the same time there are many points of difference. 



Anatomy. 



The Alimentary Canal (PL V. fig. 2). — There is a wide 

 buccal cavity from which passes a long thin-walled oeso- 

 phagus ; at the junction of the oesophagus with the crop is a 

 large bilobed salivary gland, which pours its secretion into 

 the postero-dorsal portion of the buccal cavity by a single 

 duct. In Testacella there are two salivary glands and two 

 ducts, lying on each side of the crop and opening laterally 



