DEVONIAN ROCKS OF CANADA -WEST. 



121 



ZAPHKEiirais GiGANTEA. — (Lesueur.) 



Two feet or more in lengtli, sometimes three inclies in diameter ; 

 surface with shallow rounded undulations of growth ; from seventy to 

 eighty radiating lam alias, which upon the upper surface of the trans- 

 verse diaphragms extend nearly to the centre, where they are some- 

 what flexuous ; a single septal fossette near the margin ; transverse 

 diapkragms well developed, and extending between the radiating 

 lamellae, quite to the outer wall, upon approaching which they appear 

 to be curved downwards. 



Locality and Formation, — Corniferous limestone. Rama's farm, 

 Cayuga ; and numerous other localities in Canada West, 



Fig. 22. Zaphrentis prolijica. Side view. 



Fig. 23. " " Bottom of cup, shewing the Beptal fossette, and 



smooth space, with an elongated ridge-like pseudo-columella in the centre. 



Z APHEENTIS PEOLIEIO A. — (BiUiugS .) 



Description. — Corallum simple, turbinate, curved, with a few broad 

 shallow encircling folds. Septal fossette of a pyriform shape, gradu- 

 ally enlarging from the margin towards but not quite reaching the 

 centre, variable in its position in relation to the curvature of the fos- 

 sil. E-adiating septa in the adult specimens between sixty and 

 seventy-five of the larger size, alternating with a like number of 

 smaller ones, the former in some of the individuals extending to the 

 centre on the bottom of the cup, where they are spirally twisted or 

 irregularly contorted, in other specimens not reaching the centre, 

 which is then occupied by a smooth space or often with a columella 

 elongated in a direction from the septal fossette towards the 



