(i) 32 Palaeontologia Sinica Ser. B 



The specific name is given in honor of M. Maurice Derwiduee, chief of the 

 Chaokouchuang mines, whose interest in, and recognition of the practical value of 

 geological and palseontological science, has contributed not a little to the distinguished 

 success of the great mining operations under his charge, and who gave us every facility 

 and aid in his power, in our investigation of the stratigraphy and palaeontology of the 

 Chaokouchuang region. 



Pagodispira dorothea Grabau (sp. nov.) 



Plate III Fig. 12 



High spired, with apical angle of about 24 degrees ; consisting of about 8 angular 

 whorls. Shoulder flat or very gently concave, without change of slope at suture; shoulder 

 angle in the young whorls about 90 or 95 degrees, increasing in the adult to 117 degrees. 

 Exposed portion below peripheral carina, about two thirds as wide as the shoulder in the 

 adult, apparently more nearly equal to it in the young; flat, or appearing slightly concave 

 because of the strong peripheral carina, which is somewhat thickened. Lower carina 

 strong, situated at the suture, and exposed in the penultimate whorl, because of the slight 

 separation of the final whorl. 



The species differs from P. derwiduii in the greater shoulder angle and more 

 pronounced embracing of the adult whorls, as well as in the laxity in growth of the final 

 whorl. From P. bowdeni it differs in the character of the shoulder and in the sharper 

 peripheral; and stronger lower carinse. 



HORIZON AND LOCALITY: In the upper Machiakou or Actinoceras limestone of 

 Tangshan. The specific name is given in honor of Mrs. Dorothy Dickinson Barbour, 

 wife of Prof. George B. Barbour the discoverer of the holotype, and by whom it was 

 presented to the museum of the Survey. 



Pagodispira dorothea var. laxa Grabau (var. nov.) 



Plate III Fig. 13 



This variety differs from the species in the laxness of coiling characteristic of the 

 whorls This is shown in the submature whorls by the fact that the lower carina shows 

 above the suture and in the last whorl by actual looseness of the whorl. The apical angle 

 is about 18 degrees. The lower carina is strong. 



