224 



ARTICULATA. 



GENUS SPIRORBIS (Lamarck). 



Spirorbis inornatus (Hall). 

 it". # 

 Discoid, adhering, deeply depressed or umbilicate, consist- 

 ing of about two volutions, the outer one robust, trans- 

 verse diameter the greater, the margin subangular, sur- 

 face smooth or with lines of growth which on the ex- 

 posed edge of the volution sometimes become slight 

 ridges. 



The specimens of this species are comparatively nume- 

 rous, but the greater part are without distinctive surface 

 markings. 



Spirorbis? flexuosus (Hall). 



An elongated tubular body, adhering on one side, sometimes 

 making half or three-fourths of a volution at its com- 

 mencement, and then continuing in a nearly direct line ; 

 often sinuate: sometimes occurring in groups of two or 

 three. Surface marked by strong, angular, transverse 

 ridges and fine longitudinal striae. 



This is a common species, adhering to the Strophostylus 

 and Platyostoma. 



FORAMINIFERA ? 



GENUS RECEPTACULITES (De France). 



Receptaculites subturbinatus (Hall). 



Body small, subhemispheric or very depressed turbinate, 

 with a broad base of attachment ; the upper side flat or 

 slightly depressed in the middle for a width of about 

 half the diameter, and thence curving outwards and 

 downwards to the periphery ; cell openings on the sides 



