A MONOGRAPH OP THE TERTIARY POLYZOA OP VICTORIA. 85 



I have only a few sniall imperfect fragments. It is distinguished by the wide, 

 very narrow sinus occupying almost the whole width of the lower lip. It may be 

 doubted whether it should not rather be referred to Lepralia. 



15. S. ridleyi, McG. PL XI., fig. 18. 



Schisoporella marsupium, Ridley, Pr. Zool. Soc. Lond., Jan., 1881 ; S. riclleyi, 

 McG., P.Z.V., 138. 



Zoarium encrusting. Zooecia distinct, smooth or areolated at the margins ; 

 thyrostome large, semicircular, contracted below, with a small rounded sinus in the 

 straight lower lip ; below the thyrostome a small avicularium on a large rounded 

 elevation. Ocecia large, rounded. 



M.C. Living. Patagonia and Australia. 



16. S. arachnoides, McG. PI. XL, fig. 19. 



Schizoporella arachnoides, McG., P.Z.V., 138. 



Zoarium crustaceous. Zooecia ovate, distinct, convex, smooth; thyrostome 

 semicircular, straight below, with a distinct, rounded sinus ; several (six or seven) 

 round the sinus, of which the lower on each side are a little removed from its margin. 

 Ocecia (in recent specimens) rounded, smooth, the edges usually sculptured. 



M.C. Living. Australia. 



Only the single imperfect specimen figured in which the characters are not 

 well marked. I have, however, no doubt of the identification. 



17. S. biaperta, Michelin, sp. PL XL, fig. 20. 



Lepralia biaperta, Busk, Crag. Pol., 37; Hippothoa biaperta, Smitt, P.B., 46; 

 id., H. divergens, I.e., 47; Schisoporella biaperta, Hincks, A.M.N.H., July, 1881, 



May, 1884. 



Zoarium encrusting. Zooecia broad, distinct, smooth, very slightly convex ; 

 thyrostome semicircular, contracted below and with a narrow slit-like sinus ; on one 

 side of the thyrostome a large bullate eminence on the upper part of which is an 

 avicularium with the narrow mandible directed downwards. 



M.C. Living. Arctic Seas, England, North America, Australia. 



18. S. convexa, n.sp. PL XL, fig. 21. 



Zoarium encrusting. Zooecia hexagonal, distinct, convex, surface smooth or 

 slightly granular ; a series of small areolations round the margins ; thyrostome 



