NTJDIBRANCHIATE GASTEROPODA. 



of 2 mm , and a height of 1-3"""; the hinge-part was not strong; the masticatory process was rather 

 short and slightly bent; the masticatory edge had a few series of short teeth, displaced among each 

 other (fig. 21). The tongue was of the common form; the radula was almost colourless, and had on 

 its long lower edge and short upper one 35 series of teeth (and besides a loose lying median tooth 

 below); in the radula sheath 41 series were seen, the four hindmost of which were not yet completely 

 developed; thus the whole number of series was. 76. The median teeth were slightly yellowish, the 

 lateral teeth colourless. The height of the oldest (foremost) median teeth was o-o8 mm , and the breadth 

 likewise o - o8 mm ; the hindmost ones seemed to have the same measures, as also the lateral teeth, the 

 breadth of which was o-i2 mm . The tooth-plates were of the form, which has been pointed out in the 

 other Galviuae; the strong median teeth (figs. 22 a, 23, 24, 25a) had the usual bent down hook, and 

 to each side of that four, more rarely three, denticles, of which the inner one was the more clumsy. 

 The weak, but broad lateral teeth (figs. 22 b, 25 b) showed the usual lanceolate, short hook. 



None of the hitherto known (northern) Galvinae have shown the above mentioned colours, 

 and thus the possibility is not excluded that we have here a new form. It seems not to be possible 

 to differentiate the Galvinae by means of the structure of the radula. 



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