of a Species of Echinits. 77 



Holland, to which it would be extremely difficult, if not impos- 

 sible, to assign characters capable of distinguishing it from our 

 common E. escuhittus. 



It may be proper to add, that the species which perforates 

 the rocks of the western coasts of Ireland has not hitherto been 

 described as an inhabitant of the British isles. 



IV. A Com- 



