(i) uO l\ih(iiiil<jlo(jia Siiiica Scr. B 



Lophospira obscura Grabau fsp. nov.) 

 Plate in Fig. 10 



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

 angulated l>y a pronounced shoulder angle and a less marked lower carina. Apical angle 

 about GO degrees. Shoulder flat, bounded l)elow by a heavy carina and embracing to the 

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

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

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

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

 Below the lower carina tlie Mhorl is rounded. Umbilicus apparently closed. Surface 

 characters not ascertained. 



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

 Hiver and Trenton grou])S of the central United States, but it is without the marked 

 carina near the upper end of the shoulder. Tliat is hoAvever faint in s<.)me 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. 



HoEizoN AND Locality: In the Actinoceras beds of the Machiakou limestone at 

 Tangshan. Collected by Survey expedition. 



Genus PaGODISPIRA Grabau (gen. nov, ) 



Shell with comparatixely small apical angle and subrectangular wholds, giving the 

 shell a pagodiform aspect. AVhorls without sht, but bearing a peripheral carina like that 

 of Lo'pliosxnra. One or more additional carinte may be present. Aperture subquadran- 

 gular to trapezoid, generally -with a faint anterior emargination. Umbilicus generahy 

 covered by the reflexed inner lip. 



This genus is closel}^ related to Luphmph-a 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 niore primitive branch of the LophoRpirn series in which the Avhorls 

 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 

 suggesrted 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 



