BARBADOS-ANTIGUA REPORTS 63 
eavity, Dr. Wilson has succeeded by the use of a powerfully 
projected light in securing a photograph with sufficient enlarge- 
ment to show the structure of these plates with a minuteness 
of detail never before obtained; the perforation by the water- 
pores is remarkably distinct. The depth and narrowness of the 
groove on the ventral surface of the arms, in which the soft 
structures lie, should also be noticed. 
