150 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



visits were successful, it was decided to spend the long 

 vacation at Piel, and accordingly the work was started 

 on July 15th and carried on without interruption till 

 Sept. 22nd., concluding with a visit Dec. 15-22. In the 

 present Keport we merely give a short account of the 

 methods employed, since the results obtained by their 

 means are not yet ready for publication. 



Hippolyte varians is one of the few Crustacea which 

 may be considered abundant in the neighbourhood of 

 Piel. It keeps, for the most part, to beds of weeds below 

 low-water mark, and hence its habits have largely to be 

 learnt from specimens in captivity. Compared with its 

 associates — Idothea,Mysis, and Crangon — Hippolyte is of 

 a delicate constitution, and needs constant aeration or 

 constant change of sea-water to maintain it in good health. 

 The resources of the tank-room at Piel enabled us to 

 overcome this difficulty. Fresh weed or the dead bodies 

 of its fellows serve Hippolyte as food. "With due 

 precautions specimens may be kept under observation for 

 ten days or a fortnight. 



From the nature of the beds of sea-weed in the Barrow 

 Channel a haul with weighted canvas tow-nets usually 

 contains an assortment of Hippolyte of different sizes and 

 colours. Shades of brown and yellow are abundant, 

 whilst green and red are sometimes common, sometimes 

 rare. With the large Halidrys siliquosa a dark brown 

 variety is associated ; among the fine Polyzoon 

 {Botoerbanhia) which clothes the lower parts of the 

 Halidrys stems, a speckled variety of Hippolyte occurs : 

 in the tide-pools of Foulney Island the green variety, and 

 it alone, is found among the Zoster a. 



The methods employed for investigating whether there 

 is a power of colour-change, and if so, how this power may 

 be tested, were for the most part quite simple. One 



