Inter-tidal Ecology at Narrow Neck Reef — DELLOW 
357 
Fig. 1. Map of Narrow Neck Reef, showing position of Traverses A, B, and C 
Traverse A, on Headland, top left; Traverses B and C, on Crab Island. 
water at any point surrounding the reef being 
2.5 fathoms. A thin layer of fine silt and 
mud is deposited on the gently inclined, ex- 
posed rock surface in calm weather. 
There are two drainage outlets in the vi- 
cinity: one at the southern end of Narrow 
Neck Beach, the other at St. Leonard’s Point. 
A considerable increase in both turbidity of 
water and abundance of colonial diatoms is 
apparent about these places. The area studied 
most intensively extends from the northern 
end of Narrow Neck Beach to St. Leonard’s 
Point, a distance of about five-eighths of a 
mile. 
The reef is made up of three main groups 
of rock which have been named the Head- 
land, Crab Island, and the Main Reef (see 
map, Fig. 1 ) . The Headland at the cliff base 
