THE JOURNAL 
OF 
THE LINiNEAN SOCIETY. 
(ZOOLO&Y.) 
THE PERCY SLADEX TEUST EXPEDITIONS* TO THE ABROLHOS 
ISLANDS (Indian OcEATf). 
Under the Leadership o£ Prof. W. J. Dakin, F.L.S., F.Z.S. 
Amphipoda and Isopoda. Bj^ W. M. Tatteesall, D.Sc, Keeper of the 
Manchester Museum. (Communicated by Prof. W. J. Dakin, F.L.S.) 
(Plates 1-3.) 
[Read 5th May, 1921.] 
I AM indebted to Professor Dakin for the opportunity of examining the small 
collection of Amphipoda and Isopoda which he made during his expedition 
to the Abrolhos Islands. Nine species of Amphipoda. and three of Isopoda 
were found in the collection. The number of specimens was very small, and 
considerable difficultj^ has been encountered in the endeavour to identify 
them satisfactorily. I have not been able to satisfy myself that any of the 
Amphipoda represent uudescribed species, but in almost all cases the 
specimens showed some departure from existing descriptions. The recent 
work of Chilton has, however, shown that in the Amphipoda we are dealings 
with a dominant and virile group of Crustacea exhibiting relatively endless 
variations, and the time has now arrived when it is better to determine the 
extent of specific variation than to regard each departure from the normal as 
of specific value. Future work will undoubtedly reduce the number of valid 
species of Amphipoda 
* Acknowledgement must be made here also of a grant from the Government Grant 
Committee of the Kojal Society, and a grant from the Biitish Association. 
LINN. JOUKN. — ZOOLOGY, VOL. XXXV. 1 
