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GENUS IV. EDWARDSIA (Quatuefages). 
Scola7ith%is (Gosse). 
Column long, slender, cylindrical, divided into 
three distinct regions, of which the two terminal are 
retractile within the central one. Anterior region 
forming a short thick pillar {capitulum) of less diameter 
than the central, and more delicate. Central region 
{scapus) covered by a skin {epidermis) more or less 
thick and opaque. Posterior region {physd) thin, 
pellucid, inflatable like a bladder; imperforate (?). 
Bisk sometimes flat, sometimes conical. 
Tentacles of one kind, few (less than thirty), mar- 
ginal, arranged in one or two rows ; slender, mode- 
rately long, pointed ; perfectly retractile. 
Mouth simple. No obvious gonidial development. 
ANALYSIS OF BRITISH SPECIES. 
Tentacles sixteen, transversely dashed with white ; 
capitulum purple brown, with white markings ; lives 
in sand callimorpha. 
Tentacles twenty-eight, pellucid crimson ; capitulum 
pellucid carneous ; lives in eroded rocks .... carnea. 
