TRUNCATELLINA. 107 



simple suture. Protoconch (II/2 upper whorls) smooth, 

 whitish, the following two whorls rapidly increasing in width, 

 horn-brown, rather coarsely, irregularly and very obliquely 

 striate; the three following whorls of equal width, colored 

 and striate like those above, progressively increasing in height, 

 the lower always higher than the preceding; last whorl li/o 

 times as high as the penult. On the lowest whorls are in- 

 distinct traces of a microscopic spiral striation. Suture 

 ascends a little to the aperture. The aperture is small, 

 rounded triangular, with simple, not thickened lip. Colum- 

 ellar margin gradually widening above, reflected, white. 

 Parietal wall with a thin white callus. On the parietal wall is 

 a projecting, short (not entering) lamelliform white tooth; 

 on the straight columella a longitudinal callus within, form- 

 ing a little brownish eminence, under it a distinct sinus. 



Height 2.25 mm., breadth 1 mm. (Odhner). 



Sweden: Schonen, near Krageholm, on stone wall at the 

 south end of the garden, under moss (A. Nilsson). 



Truncatellina sundleri Hj. Odhner, Arkiv for Zoologi, 

 XVI, No. 29, p. 1, figs. 1-5. 1924. 



Up to this time only two examples of this apparently 

 endemic species are at hand, which moreover are of somewhat 

 different forms. One is a little higher, though with the aper- 

 ture not fully developed, as it has no trace of the parietal 

 tooth and also a weaker columella callus. In order to clear 

 up the affinities of the new species the radulae of T. monodon, 

 T. cosiulata and T. cylindrica are repeated here. It appears 

 that the differences between T. sundleri and the other two 

 Swedish species relate only to minor details. The radula of 

 T. monodon, on the other hand, differs considerably from those 

 of all Swedish species, as the accessory cusps of the lateral 

 teeth are very unequal in length; the inner is about double 

 the size of the outer. 



The conchological affinities of the new species are the 

 reverse : it differs significantly from known Swedish species 

 by the larger shell, darker color and finer sculpture. In the 

 latter respects, as well as in the presence of a parietal tooth. 



