65 
P. Caput Meduse. The Column differs in its joints, being thinner, and their 
having been covered all over with a more conspicuous muscular coat, which 
shows itself in numerous minute tubercles, the result of its contraction. 
I apprehend that the superior extremity figured in WuiTeHURsT and Par- 
KINSON, aS mentioned above, belonged to this species. I also conceive that a 
specimen in the possession of Mr. G. Hawker, from the banks of the Severn, 
but much disfigured by pyrites, appertains to it. 
