REPORT OF THE DIRECTOR I916 I 85 



of the upper Devonian period, this species partakes of the nature of 

 the rest. 



The specimens on which the genus and species are founded occur 

 in a slab of hard siUcious Chemung sandstone found loose at Hins- 

 dale, Cattaraugus county, N. Y., and sent to the Museum by John S. 

 Johnston of Wellsville. On the weathered surface of this slab is 

 the deep impression of the large, branched specimen, (plate 6), 

 taken as the type of the genus and species. In the substance of the 

 slab several others, smaller in size, have been found preserved as 

 external and internal casts. 



ozospONGiA gen. nov. 

 Ozospongia johnstoni sp. nov. 



(Plates 5 and 6) 



Obconic, anodose, nonprismatic ; generally expanding from the 

 base up and rather abruptly constricted to well-defined ostia; 

 extended below into short or long, subcylindrical stems which join 

 at various intervals, uniting in or branching from a common stalk. 

 This stalk or stem tapers so slowly that it must at times have reached 

 very considerable length. The best expression of this compound 

 form is shown in the typical colony, where it will be observed that 

 two individuals divide the common stem equally, the branching 

 stems having about the same caliber as the parent. One of these 

 sponge cups has grown to larger size than the other, and from the 

 stem of the lesser has apparently branched off a third cup attached 

 by a much shorter stalk. The true position of this third individual 

 may quite possibly be concealed by the compression of the colony. 

 Over the surface of these bodies, particularly about the base and 

 stems, there is a perfectly evident cross-lining, indicating a network, 

 but the greater part of the surface bears irregular, low ridges run- 

 ning longitudinally and in some measure evidently due to lateral 

 compression, though some such roughened surface might well be 

 quite normal to the sponge. 



The other specimens here shown indicate variations from this 

 individual expression. Figure 2 shows a young offshoot of small 

 size, branching from the parent cup by a very short stem. In these 

 specimens the network of the reticulum is much more clearly indi- 

 cated. The stem here does not terminate so abruptly as indicated. 



