198 
Animal furnished with two fan-shaped branchiae* 
and a funnel or club-shaped corneous operculum. 
Obs . The tubes often assume the same form as the 
preceding genus; they are generally larger, often 
very large in comparison. 
Vermilia . Shell variously curved, attached by its side : 
one or more teeth occur upon the edge of the aper- 
ture. 
Animal furnished with two fan-shaped branehiae, 
and a shelly, simple, operculum. 
Obs . One or more carinae upon the tube being 
produced, form the teeth upon the margin of the 
aperture : these carinae do not always extend to the 
aperture, and are sometimes wanting in a few indi- 
viduals of the same species as those which have them 
(see S. ampullacea, tab. 597.). The operculum is 
sometimes conical, sometimes has a tricuspidate 
apex, and sometimes flat. Serpula crassa (tab. SO.) 
belongs to this genus, unless the concave radiated 
operculum would be sufficient to form a new one 
from. 
Galeolaria. Shell variously curved, attached by its side ; 
a spatulate process upon the edge of the aperture 
terminates a double keel along the back. Opercu- 
lum shelly, concave ; in its disk are inserted a num- 
ber of lanceolate moveable pieces. 
Obs. This is the most distinct genus ; but should 
it occur among fossils, it would be difficult to disco- 
ver, unless the operculum should happen to be pre- 
served. Serpula crassa is between it and Vermilia. 
Many Serpulae form septa in their tubes, as the animals 
proceed from the smaller extremities towards the larger, 
in consequence of their increased thickness. 
