106 ^N^"^ YORK STATE MUSEUM 



Cordania hudsonica sp. nov. 



FlO. Page 34 



17 An internal cast of the pygidium. x2 



18 A pygidium with portion of the exterior showing the orna- 



ment. x3 



Cordania becraftensis sp. nov. 



Page 22 



19, 20 Two pygidia, showing surface markings. x3 

 21, 22 Two cranidia, natural size 



23 A portion of the cranidium, enlarged to show the character 

 of the ornament. x2 



Cyphaspis minuscula Hall (sp.) 



Page 24 



24, 25 Two cranidia, x3 



Acidaspis tuberculata Conrad 



Page 25 



26 The cranidium. x3 



Autodetus beecheri Clarke 



Page 26 



27 The internal cast of the spiral tube lying in the natural 



mold of the fossil. x3 



28 A specimen showing the cast spiral tube and a part of 



the exterior wall 



29 The exterior of the species with a Fistulipora grow- 



ing on the surface 



30 The interior wall of the shell with the casts of the spiral 



tubes removed except that of the initial volution which 

 lies on the surface of attachment. x3 



31 The initial form of the shell, attached to the surface of a 



brachiopod. This is a highly convex bulb, which is not 

 overlapped by the early part of the first volution. x5 



32 A somewhat more progressed condition with more of the 



spiral tube remaining. x5 



