XORTH AMERICAN EARLY TERTIARY BRYOZOA. 



65 



PIG. 14. Structure of the vibraculuui. 

 A. Longitudinal section of a vibraculum of Caberca boryi Audouin, 1826. (After Calvet, 1900.) 



mcl, vibraculoid mandible or seta. 

 muab, nmndibular abductor muscle. 

 muud, mandibular adductor muscle. 

 [in, polypidian rudiment ( = abortive polypide= 

 ciliated organ = peculiar body). 



ce, external layer of the polypidian rudiment. 



ci, internal layer. 



ciiid. cavity of the vibraculoid mandible (=seta). 



cct, ectocyst. 



eiia, vibracularian epidermis. 



epf, facial epidermis. 



B. Base of vibraculum of Cribrilina latimarginata Busk, 1SS4, X 150. 



C. Lower part of vibraculum of SeJenaria maculata Busk, 1852, X 250. 



D. Base of vibraculum of Cupulatlria cunaricnxis Busk. 1852, X 250. (R-D, after Waters, 

 1888.) 



E. F. Vibracula and seta of Lunuliles patelliformis Maplestone, 1904. 



G, H. Vibracula and seta of Lunulites rrpandus Maplestone, 1004. (E-H, after Maplestone.) 

 I. Auriculated vibracula of Vt'bracelUna capiJInrin Canu and Bassler, 1917, X 20. 

 55899 19 Bull. 106 5 



