302 LANGENBECK. [VoL. XIV. 
as on the European coast from Norway to the Mediterranean.! 
It is most plentiful and accessible, and, as I was able to collect 
a complete series of embryos, it proved a very favorable species 
upon which to work. For a description of the animal I refer 
the reader to Della Valle (93), who places it in family IV, 
Corophiidae. To this same family belong also Amphitoé and 
Sunamphitoé, whose development has been described by Mlle. 
Rossiiskaya (91). Judging from the resemblance of her figures 
to those I have of Microdeutopus, the modes of development 
of these species must be almost identical; our interpretations, 
however, differ widely. 
The Corophiidae are placed in the sub-order Crevettina 
together with the Gammaridae and the Orchestiidae (Leunis), 
families whose development has received the most attention. 
Microdeutopus itself was studied by Della Valle. In his 
introduction to the embryology he says he studied not only 
the eggs of Orchestia and Gammarus, which he figures and 
describes, but also amphipods of other families, especially 
Microdeutopus gryllotalpa, as control observations. Della Valle 
is convinced from his studies that, on the whole, there is no 
essential difference in the development of these groups. There 
are many points in his description which I am not able to bring 
into harmony with what I found for Microdeutopus, but I shall 
defer the discussion of these points until I have given my own 
results. 
Methods. 
Microdeutopus lives in shallow water among decaying sea- 
weed. By taking small portions of the seaweed at a time and 
squeezing them the animals came out of hiding and could be 
easily caught. They were then placed in glass dishes with fresh 
salt water, and kept in captivity for several days. It is very 
difficult to catch the animals with eggs in the early stages, 
though why this should be so I cannot tell. Quantities of 
females with the eggs twenty-four hours old could be found 
1 Prof. Sidney I. Smith, of Yale University, who very kindly identified the 
amphipod, made the statement about its distribution in a letter to Dr. McMurrich, 
to whom I am indebted for the information. 
