162 BRUSINA : PAPVROTHECA, A NEW GENUS OF GASTROPODA. 



The best preserved and nearly complete specimen (fig. i) has 

 a height of 4/5 millim., a breadth of 1/9 millim., and a thickness of 

 o - 5 millim. The septum is about 2 millim. high. The septum of the 

 largest, but very incomplete specimen (fig. 2) is about 4 millim. ; the 

 whole shell must consequently have been about 10 millim. in height. 

 I do not think the species has reached larger dimensions than this or 

 I should have been bound to have found fragments of larger and 

 stronger apices. 



This species, of which I discovered a single specimen in 1887 in 

 Ripanj, I consider as the type of the genus. It is a very abundant 

 form, I having this year received over fifty more or less complete 

 examples or fragments. 



Papyrotheca pseudogyra, sp. nov. 



(PL 11, fig. 4.) 

 This species is very much like the preceding one, and yet so very 

 different, that although I have found only one specimen, I must 

 consider it as a distinct form. 



It is considerably smaller than P. mirabilis, the septum of the 

 external edge is not crescentric but simply diagonal. I do not, 

 however, wish to put too much weight on these circumstances, as 

 we can probably trace the reason to the fact that this is only a 

 half-grown specimen. 



The following important facts, however, have convinced me that it 

 is an absolutely good and separate species. 

 a The whole shell is more spade-shaped. 



b Although the specimen is only very small, the apex if compared 

 with the larger apex of P. mirabilis will be found to be much 

 more blunt and puffed up. 

 c In P. mirabilis the apex is turned a little sideways, but in this 



species the apex is quite straight. 

 d In the apex of P. mirabilis there is a distinct deep wrinkle on 



the back, whereas in this species it forms a regular surface. 



e If the apex is magnified, say about thirty times, there appears on 



the side of the mouth a thread shaped wrinkle or scarcely 



deepened spiral, which apparently seems to separate the apex in 



2-3 whorls. I say seems, because although I cannot sacrifice the 



only specimen, I am convinced that the said wrinkle does not 



correspond to any real interior whorls, but is simply a superficial 



spiral, which, if one cares to form a hypothesis, morphologically 



considered, will probably show a tendency to produce rotations. 



The small shell is about 2 millim. high, o"8 millim. broad, and 



a little less than o # 5 millim. thick. 



