Memoirs of the Museum of Comparative Zodlogy 
AT HARVARD COLLEGE. 
VOL ReXRC VE NOnmle 
TS ON THE SCIENTIFIC RESULTS OF THE EXPEDITION TO THE 
STERN TROPICAL PACIFIC, IN CHARGE OF ALEXANDER AGASSIZ, 
pete U. S. FISH COMMISSION STEAMER “ ALBATROSS,” FROM 
OBER, 1904, TO MARCH, 1905, LIEUT.-COMMANDER L. M. GARRETT, 
y.. COMMANDING. 
ELE: 
Pik HY DROIDS: 
By SAMUEL F. CLARKE. 
WITH FIFTEEN PLATES. 
[Pub ished by permission of Georce M. Bowers, U. S. Commissioner of Fish and Fisheries. ] 
CAMBRIDGE, U.S. A.: 
P Printed for the fMuseum. 
FEBRUARY, 1907. 
