(i) 30 Palxontologia Sinica Ser. B 



Lophospira obscura Grabau (sp. nov.) 



Plate III Fig. 10 



Shell turretecl, consisting of about 5 whorls which expand rapidly and are 

 angulated by a pronounced shoulder angle and a less marked lower carina. Apical angle 

 about 60 degrees. Shoulder flat, bounded below by a heavy carina and embracing to the 

 lower carina of the preceding whorl. Exposed part of the body of the preceding whorl 

 somewhat less than the width of the shoulder. Shoulder angle about 115 degrees, 

 characterized by a rather strong rounded carina or keel. Lower carina moderately strong, 

 the surface of the whorl between it and the shoulder angle being flat or slightly concave. 

 Below the lower carina the whorl is rounded. Umbilicus apparently closed. Surface 

 characters not ascertained. 



In its general form and character this species resembles L. bicincta of the Stones 

 River and Trenton groups of the central United States, but it is without the marked 

 carina near the upper end of the shoulder. That is however faint in some cases in the 

 American species. It differs from L. gerardi in the greater shoulder angle, smaller apical 

 angle and less degree of embracing. 



The mold of the interior of our species presents rounded outlines owing to the 

 thickening of the shell on the interior. 



HORIZON AND LOCALITY: In the Actinoceras beds of the Machiakou limestone at 

 Tangshan. Collected by Survey expedition. 



Genus PAGODISPIRA Grabau (gen. nov.) 



Shell with comparatively small apical angle and subrectangular whorls, giving the 

 shell a pagodiform aspect. Whorls without slit, but bearing a peripheral carina like that 

 of Lophospira. One or more additional carinre may be present. Aperture subquadran- 

 gular to trapezoid, generally with a fa.int anterior emargination. Umbilicus generally 

 covered by the reflexed inner lip. 



This genus is closely related to Lophospira from which it differs primarily in the 

 much drawn-out form of the spire, and the resultant small apical angle. It may indeed 

 be regarded as a more primitive branch of the Lophospira series in which the whorls 

 embrace only to a very small degree, or better as a lateral branch from the ancestral 

 stock, in which the embracing of the whorls remains in the primitive state. This is 

 suggested by the fact, that in other gastropod series the more specialized members show a 

 larger amount of embracing, while further, members of a degenerating series, show a- 



