574 



MISS MUNKO ON NEW TREPOSTOMATOUS 



[Dec. 1912, 



Appendix II. 



Description of some New Forms of Trepostomatous Brvozoa 



from the Lower Carboniferous Rocks of the 



North-Westerii Province. By Madeline Munro, B.Sc. 



SlEIiJOPHRAGMA, gGD. DOV. 



Zoarium ramose or irregular, lobate and folded ; branches 

 generally hollow and lined by an epizoarium ; zooecia of varying size, 

 the largest sometimes occupying distinct monticules at the surface; 



periodical thickening of 

 — Longiludinal section of a branch 

 of Stenophragma lobatum, corisisting 

 of only one layer, showing strong ejn- 

 zoarium (e), zooecia {z),diapliragms (d), 

 in the matwe region, and the characters 

 of the lualls. x about 20 diameters. 



Fig. 8. 



Mr ^ 



the walls in the mature 

 region well marked in 

 man}- species; d i a- 

 phragms present in the 

 mature region, incom- 

 plete and very narrow, 

 only attached to the 

 proximal walls ; acan- 

 thopores present or ab- 

 sent ; no mesopores, but 

 cells much smaller than 

 the average are observed 

 occasionally. 



Stenophragma loba- 

 tum, gen. et sp. nov. 

 (Figs. 8-10.) 



Zoarium composed of 

 one to three layers, each 

 having a thickness of 1 

 to 2'5 mm., epizoarium 

 strong and wrinkled ; 

 branches hollow, irregu- 

 larly lobate or folded, 

 having a diameter of 

 from 5 to 20 mm. ; zo- 

 oecial apertures usually 

 polygonal, sometimes 

 subcircular ; three to 

 four ordinary zocecia occupy 1 mm. ; monticules quite conspicuous, 

 each occupied by eight or more zooecia nearly half as broad again as 

 the rest, the centres of these groups being at distances of 4 to 5 mm. 

 from one another. Zooecial tubes thin-walled and oblique at first, 

 then making an angle of about 120° they proceed directly to the 

 surface, the walls at the same time becoming much thicker and 

 the tubes broader ; the walls are periodically constricted. The 

 numerous narrow crescentic diaphragms arise at very constant 

 levels in neighbouring zocecia, and always from what were the 



[Two of the diaphragms in the above figure are 

 wrongly shown open at the tip.] 



