678 



MISS MIJNRO ON NEW TKEPOSTOMATOTJS [DeC. I912, 



the mature region. Zooecia prismatic and thin-walled in the axial 

 region, diverging gently from an imaginary central axis to open 

 directly at the surface ; usually, eight to ten zooecia occupy 5 mm. 

 in all parts of the zoarium ; apertures rounded and large ; walls 



Fig. 11,— Longitudinal section of a branch of Stenopora compacta, 

 sp. nov., comjyosed of two layers : showing zooecia (z) traversed 

 by complete diaphragms (d), small cells, possibly mesopores (s), 

 acanthopores (a), and the characters of the lualls in the mature 

 and the immature regions. X about 20 diameters. (From the 

 Bryozoa Band, Weather Hill, iShap District.) 



unequally thickened in the mature region, but seldom sharply con- 

 stricted. The zooecia are traversed by thin, complete diaphragms, 

 which are rare in the axial region but numerous in the mature 

 zone, seldom being separated by distances greater than their 

 own diameter; the majority are straight and horizontal, but some 

 are very oblique, others curved, and often an oblique and an hori- 

 zontal one appear to coalesce or have a common origin on one side. 

 Small cells, often irregularly moniliform and without diaphragms, 

 occur singly at many of the junction-angles. Acanthopores few, the 



