﻿Study of the Animal Ecology of the Shore. 



251 



namelT, of Hyale nilssoni with Gammarus marinus. 

 They occur commonly on seaweeds, but Gr. marimis is 

 found also under stones. Their association presents 

 an interesting and simple problem for experiment. 

 Amphithoe ruhricata is not so distinctly a shore form 

 as the other species here tabulated. 

 ISOPODA. — Jccra albifrons seemed specially abundant in 

 Zone 2, Upper. Only the young of Ligia oceanica were 

 found below high-water mark. They are remarkably 

 quick in their moyements. The adults seem to ayoid 

 immersion.^ 



PoTcellio scaher, a well-known terrestrial form, was 



found in the Drift. 

 Brachtuea. — The only point deserving mention is the 



occurrence of megalopas of Carcimis mcenas in Zone 3. 

 Ptcnogoxida. — PhoxicMlidmm femoratum is frequently 



found in association with little scraps of a dark-red 



alga FuTcellaria furcata, to which the adults bear 



rather a deceptive resemblance. 



IV. Ge]nt:eal Eemaeks. 



Ve must, in the first place, repeat our former statement 

 that we present here, not results of importance in them- 

 selves, but an account of an experiment which was designed 

 to test a method in actual working. 



The system we have outlined, to produce results of 

 general interest, would rec[uire to be in action for at least 

 a year. Further, a series of stations of the same type of 

 shore, and of different types, would have to be examined 

 at regular intervals during a like period. It must not be 

 supposed that the adoption of a system " relieves the 

 collector of the necessity for alertness in observing inter- 

 relations, which might be missed in the analysis of the 

 tabulated facts. There are many facts which can be more 

 readily discovered by direct observation than by a laborious 

 siftincr of accumulated results. 



^ During the printing of these notes vre have found (May 1909) numerous 

 adults of Ligia sheltering at high tide under stones immersed, close to high- 

 water mark. 



