THK NAUTILUS. 33 



to be ;i deformed or abnormal Anialia. This view was adopted by 

 Tryon and others; Morch, Binney and Fischer having doubted the 

 very existence of such a slug. 



In examining the slugs of the Vienna Museum lately. Dr. Babor 

 found Fitzinger's specimens, and he also obtained fresh individuals 

 collected by Dr. Sturany in northern Steiermark, and by Dr. Wer- 

 ner in Montenegro. These specimens prove that Aspidoporns limax 

 is not only a valid species, correctly observed by Fitzinger, but it 

 belongs to a special group of at least subgeneric value. 



The mantle is formed as in Amalia, having the impressed " horse- 

 shoe," but there is a small orifice which in some specimens penetrates 

 to the shell-sack, while in others it is merely a short, sharp impres- 

 sion, not penetrating through the mantle. The shell-plate is small 

 and moderately thick. Pallial organs and nervous system as in 

 Amalia, and the jaw and teeth are also not peculiar, except that the 

 former is a little notched in the middle, below. The intestine is 

 somewhat peculiar. There are six longitudinal folds. G, and the 

 lower part of G fi (forming the last posterior loop), being independent 

 of the spiral torsion of the normal Amalia folds, lying to one side. 

 There is no ccecum. 



In the genital system the accessory gland (characteristic of 

 Amalia), is completely wanting. 



Dr. Babor, in discussing the systematic position of Aspidoporns 

 and Amalia, gives evidence for regarding them as independent of the 

 Limacidig, and as a branch from the family Helicida (in the narrow 

 sense). The main argument for this view is that the ftmbryologic 

 origin of the spermatheca is diverse in the two groups, Amah'a being 

 of the Helicid triaule type, while Limax is of the diaule type. An 

 adequate discussion of this question would require more space than is 

 available in this place; but it should be said that the well-developed 

 pedal grooves show Amalia to lie a typical Aulacopodous snail, and, 

 therefore, far removed from the Il> Ucidce : while the particular modi- 

 fication of the retractor muscle system distinctly points to the Lima- 

 cidce. Tli is is not likely to lie a wholly independent parallel evolu- 

 tion. Moreover, I fail to see any such resemblance between the 

 intestinal arrangements of Aspidoporns and the Helices as Dr. Iiabor 

 alludes to, though the nut is wholly unlike that of Limax. 



It is very gratifying to have the real existence of Aspidoporns 

 proven, especially as the genus is undoubtedly more primitive than 



