﻿Shtdy of the Aniinal Ecology of the Shore. 



2-19 



shown by their occurrence in positions where they are 

 exposed to fresh water. It is probably to this power that 

 they owe their ability to occupy the higher reaches of 

 the shore. 



2. Xotes on the Species. 



Peotozoa. — The scarcity of Foraminifera was remarkable. 

 Possibly it may be explained by the abundance of 

 fresh water in the area. 



PopjFEEA.. — Xoue of the species were found in situations 

 exposed to fresh water. Only two species, viz., Leucoso- 

 lenia lotryoides and Halichonclria panicea, were found 

 as far up as Zone 2, Lower. The base of Laminaria 

 appears to be a favourite position for several species. 



Hydeozoa. — The distribution in depth is similar to that 

 of the Sponges, but they occur in more exposed 

 positions, e.g., on the upper surface of stones, and ou 

 the fronds of Ascophyllum and Fucus sermtus. Only 

 one species was found in fresh water, viz., Coryne 

 jpusilla. Clava multicornis is found only on the under 

 surface of stones. Tuhularia simplejj and Clytia 

 johnstoni here appear to be confined to Zone 4. They 

 are well known to occur at greater depths in the 

 Laminarian region, and are not purely shore forms. 



AcTiyozoA. — The chief feature of note is the ubiquity of 

 Actinia equina. 



Urticina felina does not seem to occur above 

 Zone 3. 



TuEBELLAELi. — Procerocles ulvce, like Actinia equina is 

 ubiquitous. It occurs all over the shore, but is 

 commonest where a stream of fresh water flows over 

 the beach. In such a stream it mav be found in Q:reat 

 abundance right up to high- water mark, where it stops 

 absolutely. This is rather remarkable, for experiment 

 has shown us that it can endure immersion in fresh 

 water for at least two days. 



Lejjtoplana tremellaris, found in Zone 4, is not strictly 

 an animal of the shore. 



OLiG0CH-i:TA. — These, as we should expect, are found prin- 

 cipally in the Drift and on the upper reaches of the shore. 



