44 



DAWSON AND HINDE 



be a wide osculum above, aud very numerous slender anchoring spicules below. There 

 are also indications that, in mature specimens, the general form sometimes became cylin- 

 drical or inverted couical, though specimens showing these forms are too imperfectly 

 preserved to show the details of structure. 



In this species and P. cijalhiformis, the wall of the body seems to have been denser 

 than in the other species and sometimes to have preserved its outward form, and this, 

 with the multitude of minute spicules and the undeveloped condition of the spicular 

 meshes of the skeleton, may possibly indicate a generic difference. 



On this species Dr. Hinde remarks : — " This sponge has a subcircular outline ; the 

 central area is vacant and there is often a relatively wide rim of a blurred mass of iron 

 pyrites with an outer margin of fairly large cruciform spicules. The iron pyrites evi- 

 dently represents a mass of spicules too small and too closely associated together to be 

 separately distinguished in their replaced condition. The sponge is clearly hexactinellid 

 and quite distinct from the others described above." 



Genus CYATHOSPONGIA [Cyathophjcvs), Walcott. 



(T. — Cyathospongia Quebecensis, S.N. 

 (Figs. 16 and 1*7. PI. Ill, fig. *!.) 



Fio. 10. — Cyathospongia Quebecensia. 

 Restored. 



Fig. 17. — Cyathofpongia Quebecensis. 

 Base enlarged. 



Form elongated conical, composed apparently of numerous long, vertical spicules, 

 crossed by horizontal or annular bars, and with a few cruciform spicules in the meshes. 

 The vertical and transverse spicules may be cruciform spicules arranged vertically. The 

 form terminates downward in a blvrnt point with indications of a few short anchoring 

 spicules. This species closely resembles Cyatliophycus {Cijathospongia) reticulatus of Walcott 



