:Z12 CONTRIBUTIONS TO CANADIAN PALAEONTOLOGY. 



in the degree of slenderness of the colony, that it is often very diflS- 

 cult if not altogether impracticable, to distinguish between H. Cana- 

 densis and S. filifonnis. Under these circumstances the writer is 

 inclined to doubt whether the characters which have been relied upon 

 to separate them are either permanent or of specific importance. 

 According to Professor jSTicholson, his A. filifonnis is "a much more 

 robust species" than H. Canadensis, "with larger tubes, and much 

 more iiTegular methods of growth and apertures generallj^ distinctly 

 elevated above the treneral surface." 



Proboscina laxa. (N. Sp.) 



Plate 28, iigs. 9, 9a. 



Polyzoary creeping, adnate and attached hj its whole under surface 

 to some foreign bodj^, spreading laxly and very irregularly branched, 

 usually with numerous short branches proceeding from two or three 

 widely divergent and procumbent tubular axes all of which are sub- 

 cylindrical in transverse section, rather narrow and slightly swollen 

 ojiposite the apertures of the cells. Cells entirely immersed, irregular 

 in their disposition, but usually obscurely alternating biserial, the 

 terminal ones subovate in outline: cell apertures not quite terminal, 

 averaging a little less than one half the greatest breadth of the colls, 

 subcircular in outline, with slightly elevated, simple and thin lips. 



Surface smooth. 



Hay Jiiver, fbrty miles above its mouth, E. G. jMcConnell, 1887 : one 

 perfect specimen, attached to Orthis striatula. 



Stomatopora moniliformis. (N. Sp.) 



Plate 28, fig. 10. 



Polj'zoary minute, creeping, attached by the whole of its under sur- 

 face to some foreign object, very slender and fragile, consisting of a few 

 irregularly disposed but more or less divergent rows of single cells, 

 which, though uniserial, occasionally throw off lateral buds consisting 

 of one or more cells, and which may, as in the specimen tigured, pro- 

 ceed from a central or subcentral irregular aggregation of cells. Colls 

 moderately convex, elliptical in marginal outline, averaging half a 

 millimetre in length, about one third longer than broad and placed end 



