J^RA ALBIERONS. 319 



J. alhifrons probably occurs all round our coasts. We 

 have it recorded on the Devonshire and other coasts, 

 among sea- weeds and under stones, in many parts of the 

 British islands. It was found especially abundant in 

 crevices of rocks at lialf-tide near Falmouth, by Mr. W. P. 

 Cocks, and we have taken it abundantly beneath and 

 generally attached to the under surface of stones between 

 tide-marks in Plymouth Harbour, the flat surface of the 

 body enabling the animal to ensconce itself in very slight 

 crevices. The late Dr. Johnston also forwarded it to us 

 from the Berwickshire coast. 



