82 Mv. R. Kirkpcatrick on the 



Genus Escharoides. 

 Escharoides discus^ n. sp. (PL IX. fig. 6.) 



Zoariam discoid, spreading hj a thin calcareous lamina ; 

 marginal zooecia decumbent, central erect, heaped up ; sur- 

 face of zocecia hyaline, verrucose ; primary orifice semicir- 

 cular, entire, not toothed ; peristome at first shallow and 

 notched, with an avicularium with pointed mandible on inner 

 side of one of the processes forming the notch j avicularium 

 forming a prominent triangular projection ; peristome in older 

 zooecia high, tubular, crowned by blunt processes ; an avicu- 

 larium on the front of the cell with triangular mandible pro- 

 jecting forwards and upwards. Ooecia small, globular, punc- 

 tured. 



In one of the specimens one disk is superimposed on an 

 older colony. In old cells with a tall peristome the internally 

 projecting avicularium appears like the denticle present in 

 Smittia &c. 



Family Reteporidae. 



Genus Retepora. 



Betepora tetiuis, n. sp. (PI. VII. fig. 6.) 



Zoarium with large oval fenestra, much wider than the 

 slender trabeculse. Surface or' zocecia verrucose, semihyaline ; 

 primary orifice semicircular, secondary orifice orbicular ; 

 peristome with fissure and preeoral pore (often obliterated) ; 

 very small spatulate avicularia scattered over the zoarium. 

 Dorsal surface glistening, granulose, divided into irregularly 

 shaped areas. Ooecia lofty, prominent, with trifoliate stigma 

 consisting of a long, broad, vertical arm terminating at the 

 summit of the ooecium in an umbo, the other two arms sliort, 

 just above the orifice. 



The specific characters consist in the large fenestra3, slender 

 trabeculee, absence of specially situated avicularia, or of avicu- 

 laria with pointed mandibles, the shape and markings of the 

 ooecium. In one or two ooecia lateral pressure has caused the 

 horizontal arms to curve inwards, so as to meet and form a 

 small complete circle. 



Chitinous appendages consist of the small semicircular 

 mandibles, of the circular avicularia, and of the operculum, 

 which is semicircular, with straight lower border (see PI. VII. 

 fig. 6c). 



Retejjora Hincksii^ n. sp. (PI. VII. fig. 7.) 

 Zoarium erect, branching in one plane ; branches free, sub- 



