BRACHIOPODA. 181 



Crania favincola, sp. nov. 



PLATE IV H, FIG. 3S. 



Two interiors of the lower valve attached to a colony of Favosites pirum 

 have very strongly developed muscular and vascular impressions. The poste- 

 rior scars are large and their strongly elevated margins unite with the broad 

 lateral border of the shell. The anterior scars are situated in front of the 

 center and are partially enveloped by the great elevation of the anterior and 

 median fulcra. The vascular sinuses are broad, slightly undulating grooves, 

 extending from the median region to the anterior border. Length, 17 mm., 

 width, 21 mm. 



Hamilton group. Crab Orchard, Kentucky. 



Craniella Ulrichi, sp. nov. 



PLATE IV I, FIGS. 1,2. 



Shell moderately large. Outline normallj' circular. Apices subcentral, slightly 

 posterior, inclined backwards. Upper valve with the posterior scars large 

 and the adjusters well defined ; anterior scars subdivided, the outer or poste- 

 rior portion possibly representing the insertion of the brachial muscles. 

 The vascular sinuses make a 3-shaped curve on the lateral portions of the 

 valve, with the crest of the double arch toward the center; narrowing rapidly, 

 becoming indistinct over the anterior region. Lower valve regularly convex, 

 evidently unattached at maturity Anterior adductors very large, situated on 

 a thickened posterior area Posterior adductor and adjuster scars very faint, 

 lying just within the margin. The vascular sinuses are a series of low 

 grooves extending forward in subparallel lines from the' anterior and lateral 

 margins of the central muscular area. External surface of the valves smooth 

 or covered with concentric sublamellose growth-lines. Length of an upper 

 valve, 11 mm., width, 12 mm. ; diameter of a lower valve, 16 mm. 



Trenton shale. Minneapolis, Minnesota. 



