220 MICROPORELLID^. 



Genus DIPORULA, Hincks. 



Der. From Sh, double, and iropos, an opening. 



EscHARA, part., auctt. 



DiPOKULA, Hincks, Ann. N. H. Feb. 1879, 156. 



Generic Character. — Zocecia with the orifice arched 

 and expanded above, contracted below, and slightly con- 

 stricted by two lateral projections [horseshoe-shaped) , lower 

 margin straight; a semilunate pore on the front ivall. 



AVICULARIA. 



Distinguished from Microporella by the structure of 

 the orifice^ which exhibits much the same type of form 

 as we have in the genus Lepralia ; and, so far as the 

 British species is concerned, by its dendroid zoarium with 

 cylindrical branches. 



DiPORULA VERRUCOSA, Pcacll. 

 Plate XXXI. figs. 1, 2. 



EscHARA VERRUCOSA, Feach, Joum. Roy. Inst. Cornwall, iii. (1868-70), 116; 



figured in vol. iv. (1871-73), 88. 

 EscHARA LUNARis, Waters, 'Bryozoa from the Pliocene of Bruccoli (Sicily),' 



11, fig. 9. 



Zoarium of a light brownish colour, dichotomously 

 branched, the branches cylindrical, rather thick, of 

 about equal size to the extremities. Zocecia disposed in 

 about seven longitudinal rows, quincuiicial, ovate, 

 slightly convex ; the surface smooth in the young cells, 

 and more or less pitted, a row of large punctures round 

 the margin ; in the older jjortions of the zoarium the walls 

 are much thickened, rugose, and covered with wart-like 

 prominences, and the boundaries of the cells are oblite- 

 rated; orifice somewhat raised, longer than broad, 

 arched above, slightly constricted below the middle, 

 the sides inclined inward, lower margin straight ; the 



