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GENUS II. PEACHIA (Gosse). 
Siphonactinia (Dan. et Kok.). 
Column cylindrical, pear-shaped, or swelling in the 
middle, rounded at the posterior extremity, where 
there is an orifice ; margin entire, forming an indis- 
tinct parapet. Surface smooth, without loopholes, 
but studded in every part with very minute and very 
numerous suckers. 
Disk flat, or very slightly conical, smooth. 
Tentacles of one kind, twelve, thick, short, obtusely 
pointed ; marginal ; imperfectly retractile. 
Mouth not elevated on a cone ; lip thin, abrupt, pro- 
trusile, sometimes lobed. A single gonidial groove, 
the edges of which are soldered together so as to 
form a tube, which terminates above in a thickened, 
expanded rim {conchula), the margin of which is more 
or less divided. 
Acontia wanting. 
ANALYSIS OF BRITISH SPECIES. 
Column lengthened. 
Conchula with from 12 to 20 lobes hastata, 
Conchula with 3 ovate lobes triphylla. 
Column short. 
Conchula with 5 shallow lobes undata. 
