MOLLUSCA OF INDIA. 173 



Size : major diam. 10-5, alt. axis 3*8 mm. 



A^iimaUfrom. a soaked specimen). Colour olivaceous with mottlings 

 on the foot ; the membrane of the branchial cavity has a margin of 

 black on the side of the elongate kidney and the visceral sac is 

 darkly mottled. The mucous gland linear, extremity of foot square. 

 Shell-lobes black, the right shell-lobe (fig. 7) broad and spreading 

 along the side of the body-whorl ; the left shell-lobe (fig. 7 a) also 

 a broad lappet and elougately triangular in shape. The male organ 

 resembles that of A. giyas, and the amatorial organ is larger. 



Jaw (fig. 7 h) with a very small central projection. 



Eadula (fig. 7 c) has the formula 



70 . 2 . 15 . 1 . 15 . 2 . 70 



87 . 1 . 87 



The central tooth and the admedian teeth are of the usual form : 

 the central tooth as drawn is malformed or broken, it is only the 

 remnant of the usual tricuspid form ; the laterals are evenly 

 bicuspid. 



The genus Auxtenia contains a very large number of species, 

 which differ in many ways from the type species and inter se ; yet 

 I continue in this work to use this generic name in its widest sense, 

 because the differences lie sometimes in the shell, without any 

 corresponding change in the internal organs, and vice versa. Sub- 

 generic groups will, sooner or later, have to be decided on ; but 

 until the anatomy of many more species is known, I think it 

 premature to do so. 



Mr. Cockerell has, I note, removed two species from Austenia, 

 viz. scutclla and pJanospira, and created two new genera on 

 apparently external characters. This is indicated first in his 

 'Notes on Slugs,' 1891, in the 'Check-list of Slugs,' 1893, and 

 published in 'The Nautilus,' vol. xii. May 1898, p. 10. The 

 genera are Euaustenia and Cryptaustenia, but without description. 

 With these also was founded another subgenus of Ibycus, viz. 

 Cryptibycus, type /. magnijicus, Nevill & G.-A., which I will refer 

 to under that genus. 



When the characters on which these genera were founded are 

 not specified, little help is rendered towards a natural system 

 of classification ; iu fact, it becomes more difficult than ever to 

 locate in the new genera many species of which the animals are as 

 yet unknown. We will take, for instance, Cryptaustenia piano- 

 spira, with all its characters, internal as well as external. The 

 only other species which I can at present place with it is Austenia 

 silcharensis, the male organ in both being of similar type — the 

 radula also ; but Austenia zemoensis cannot be included in Crypt- 

 austenia, because the genitalia are quite different (vide Plate CVIL). 



In Vol. II. part ix. p. 93, under Austenia planospira, I pointed 

 out that the generative organs differed from those of Austenia ffigas, 

 and on the other hand were like those oi EurychJamys, and suggested 



