118 ROYAL SOCIETY OF CANADA 



IXCERTiE S EDI S. 



15. Non-Spiculate sponges. — Pyritous spots of indeterminate fovm, 

 and sliiAvini;- under the lens only an oliseure granular and tloeculent ap- 

 ]>earanee are not infrequent on the surfaces of the Metis shales. In addition 

 to these, however, there ai-e two types of these objects of more definite 

 shape, either triano-vilar with a dark s])ace in the centre or oval. The 

 former seem to be flattened hollow cones, the latter possibly flattened 

 sacs. Some of the former show sutflcient traces of sjiicules to connect them: 

 with Protospongia cyathiformis, while others may be entirely pj'ritized 

 individuals of P. (leUratiila. In addition to these, however, there are 

 others which, under the lens and when moistened, show indications of 

 simple linear spicules, and more numei'ous examples which seem to be 

 composed of indeterminate and interlaced fibres reminding one of the 

 tissue of a corneoiis sponge. None of them have any indications of 

 anchoring rods. For the present L merely mention them as possibly 

 indicating types of sponges distinct from any of those above described. 



16. Spiculate sacs. — Imbedded in the debris of the larger specimens 

 of Hyalostelia, there are oval flattened patches made up of a dense mass 

 of very small and apparently simple spicules, but presenting no aperture 

 or anchoring-rods. Having found them only in connection with Hyalo- 

 stelia, I at fii-st imagined they might Ije some form of ovarian body ; 

 but Dr. Hinde doubts this, and is inclined to regard them as distinct 

 organisms. One of them is represented in Fig. 30 of about the natural 



Fiti. 'M. — Spiculate sac, found 

 with Hyalosteha. 



size. If distinct sponges, there nuiy have l)een some commensal relation 

 between them and Hyalostelia. They are quite distinct from the little 

 masses of broken spicules referred to above in Section IV. 



17. Minute Globi;lar or ('frcular Bodies. 



Surfaces of an inch oi" nioi'c in dianictei" ai'e occasionally sti])])led 

 with minute pyritous spots ; Avhen magnified these appear perfectly round 

 and of apjjnjximately uniform dimensions. They may either be inor- 



