0RISKANY FAUNA OF BECRAFT MOUNTAIN 107 



Spirorbis assimilis sp. nov. 



Fio. Page 26 



33 A group of these tubes on the internal surface of a valve 



of Meristella 



34 The upper surface of a specimen. xlO 



Cornulites cingulatus Hall 



Page 27 



35 A small tube attached to the edge of a valve of Ortho- 



thetes. x3 



36 A larger example. x3 



37 A large tube, showing surface of attachment to a Fistu- 



1 i p o r a . x3 



38 Internal cast of another specimen. x3 



