HALF AN HOUR WITH SEA-WORMS. 



75 



condition, amid the oozy mud, the serpulae were glad 

 to find a place where they could attach themselves, 

 and in finding it on these shells, &c., they plainly 

 tell us the chalk did not accumulate fast enough to 

 bury them whilst they were living. The interior as 

 well as the exterior of fossil shells is frequently 

 found overrun by serpulse, showing how the former 

 had died, and the ligament which held the valves 

 together been decomposed, before the mud collected 

 over them. Two very common, but exceedingly 

 minute tubed-worms, allied to the serpulse, are the 

 Spirorbis communis and nautiloides (Figs. 32 and 33). 



Fig. 32. 



Fig. 33. 



Spirorbis nantiloides on Fucus 

 serratus, nat. size. 



Spirorbis nautiloides, 

 X 25. 



They are usually found adhering to the backs of the 

 common sea-wrack, in many cases almost covering 

 the fronds with their little coiled shells. The 

 worms inhabiting these abodes closely resemble the 

 serpula. They possess six branchial filaments, of a 

 rose-pink tint, and the peduncle or plug, which look 

 strikingly like angels' trumpets. A species nearly 

 allied to these is abundant, in the fossil state, in the 



