(i) 32 Palxontologia Siaica Ser. B 



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

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

 geological and palteontological 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. no v.) 



Plate III Fjg. 12 



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

 Avhorls. Shoulder flat or very gently concave, without cliange of slope at suture; shoulder 

 angle in the young wdiorls about OU or 93 degrees, increasing in tlie 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, liceause of the slight 

 separation of the final whorl. 



The species differs from P. dericiduii 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 F. hoivdcni it differs in the eharactcr of the shoulder and in the sharper 

 peripheral; and stronger lower carinie. 



Hiniizi.ix A^'i) Locality: In the upper Machiakou or Actinoceras limestone of 

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

 A\ife of Prof. Georg(/ B. Barbour the discoverer of the holotype, and by Avhom it M'as 

 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 l)y the fact that the lower carina shows 

 above the suture and in the last whorl ]jy actual looseness of the ^\•horl. The apical ano-le 

 is about 18 di'grees. The lower carina is strong. 



