NORTH AMERICAN EARLY TERTIARY BRYOZOA. 
65 
Fig. 14. — Structure of the vibraculum. 
A. Longitudinal section of a vibraculum of Caberea boryi Audouin, 1826. (After Calvet, 1900.) 
ce, external layer of the polypidian rudiment, md, vibraculoid mandible or seta. 
ci, internal layer. muab, mandibular abductor muscle. 
and, cavity of the vibraculoid mandible (—seta), n iuad, mandibular adductor muscle. 
ect, ectocyst. pa, polypidian rudiment (=abortive polypide= 
epa, vibracularian epidermis. ciliated organ=peculiar body). 
epf, facial epidermis. 
B. Base of vibraculum of Cribrilina latimarginata Busk, 1884, X 150. 
C. Lower part of vibraculum of Selenaria maculata Busk, 1852, X 250. 
D. Base of vibraculum of Gupuladria canariensis Busk, 1852, X 250. (B-D, after Waters, 
1888.) 
E. F. Vibracula and seta of Lunulites patellifonnis Maplestone, 1904. 
G, H. Vibracula and seta of Lunulites repandus Maplestone, 1904. ( E-H , after Maplestone.) 
I. Auriculated vibracula of Vibracellina capillaria Canu and Bassler, 1917, X 20. 
55899— 19— Bull. 106 5 
