Seitaro Goto 
On two species of Hydractinia living in symbiosis with a lier- 
mit crab. From the Zoological Laboratory, Imperial Uni- 
versity, Tokyo, Japan. Twenty-three figures. 469 
Hubert Lyman Clark 
The development of an apodous holothurian (Chiridota roti- 
fera). From the Museum of Comparative Zoology, Harvard 
University. Six figures 4 
Henry L. Osborn 
On the structure of Cryptogonimus (nov. gen.) Chyli (n. sp.), 
an aberrant distome, from fishes of Michigan and New York. 
From the Biological Laboratory, Hamline University. Seven 
figures 517 
H. V. Wilson 
A study of some epithelioid membranes in monaxonid sponges. 
From the Zoological Laboratory, University of North Caro- 
lina. Twenty-one figures 537. 
Charles Wilson Greene 
An experimental determination of the speed of migration of 
salmon in the Columbia River. From the Physiological 
Laboratory, University of Missouri. Two figures 579 
T. H. Morgan 
Cytological studies of centrifuged eggs. From the Zoolog- 
ical Laboratory, Columbia University. One hundred and 
eighteen figures 593 
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