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DESCRIPTION OF A NEW SPECIES OF TRACHIOPSIS FROM 

 BRITISH NEW GUINEA. 



By H. B. Preston, F.Z.S. 



Read 9th December, 1904. 

 Planispira (Trachiopsis) Blackiana, n.sp. 



Shell depressed, fulvous brown, the peristome slightly tinged ivith 

 pinkish purple. Whorls 5, convex, well marked with coarse striae 

 which almost appear as riblets, especially on the later whorls, possibly 

 indicating periods of rest, and with finer lines of growth between 

 them. Suture well-impressed. Aperture suboval. Peristome reflexed 

 and descending above, the extremities united by a slight callosity. 

 Columellar margin rather broadly expanded, whitish. Umbilicus 

 deep and rather narrow, though rapidly broadening towards the base 

 of the shell. 



Diam. maj. 21mm.; alt. 10 mm. Aperture (inside measurement), 

 diam. 7 mm., alt. 7"5mm. 



JIab. — Port Moresby District, British New Guinea. 



A very striking shell, whose nearest ally appears to be T. JDelessertiana, 

 Le Guil. From this, however, it differs in its more solid appearance, 

 in its rather deeper suture and somewhat more circular aperture, and 

 in the purplish tinge on the outer lip, which is absent in T. Delessertiana ; 

 moreover, the riblets appear to be quite peculiar. 



I have received several specimens through the kindness of Mr. P. G. 

 Black, with whose name I have much pleasure in associating the 

 species. Although there appears to be some variation in size, all the 

 other characters are absolutely constant. 



