[DAWSON] FOSSIL SPONGES AND OTHER ORGANIC REMAINS 



117 



Many tViiifineiits t»l' this species have l)oen ibund from time to time, 

 bliowiiii;' ionjf stout taporiiii; anchorinjij-rods with masses of long slender 

 simple spicuk's near them ; hut in 18!t5 for the first time nearly perfect 

 specimens were ohscrvcd. They consist of discs somewhat lari^er than 

 tho!J« of S. satirt((. made up of fine straight spicules radiating from a intint 

 near one side and i-ather coai-ser tluin those of S. sancta, and showing 

 here and there a tendency to he aggregated more densely as if in hundles, 

 Itut this is not very marked. At and toward the circumference there are 

 occasionally a few very snndl cruciform spicules which, as they are not 

 confined to one specimen, I regard as prohahly the remains of an outer 

 or cortical layer. If they are accidental tliey must he the smaller spicules 

 of disintegrated Protospongia^ entangled in the spicular surface of Ste- 

 phanella. It seems more likely, however, that they are a i)art of its 

 structure, in which case it furnishes an example of a sponge with a dense 

 internal skeleton of radiating spicules. Fig. 27 represents a nearly 



iSlk^' 



Fi(». 2S.—StephaneUa Hindii. Fragment Fi(i. '29.—StephaneUa ? Anchoring- 

 with anchoring-rods. rods and part of the spicules, enlarged. 



complete specimen, and Figs. 28 and 29 disintegrated fragments with the 

 anchoring-roots, whi(d\ in some specimens are longer and more tapering 

 than in others, though always very stout at the hase. 



In Dr. Ami's specimens from Ottawa, a few stout anehoring-rods 

 and cruciform spicules are found in the same dahs with Stei^hanella, hut 

 none of them are seen to he attached. I think it not improhable, how- 

 over, that the former, at least, belong to Stephanella. 



