145 
GENUS V. GREGORIA (Gosse). 
Base not broader than the column. 
Column a low pillar, strongly invected, very in- 
flatable in irregular lobes ; the margin forming an 
irregularly undulate parapet, separated from the ten- 
tacles by a deep but narrow fosse, which is never 
obliterated. Surface smooth, but becoming trans- 
versely wrinkled in contraction ; without suckers ; 
perforated with few, but very conspicuous loop-holes ; 
these are arranged in longitudinal lines, on the swell- 
ings, which correspond to the intersepts. Substance 
pulpy. 
Dish plane; not exceeding the column; smooth, 
without conspicuous radii. 
Tentacles moderately short, blunt, unicolorous ; not 
perfectly retractile. 
Mouth set on a cone ; lip thin ; two gonidial grooves, 
each with a pair of small tubercles. 
Aconlia emitted sparsely. 
L 
