Itmotrs of i^t gtus^um of Comparatib^ ^oolo^n 



AT HARVARD COLLEGE. 



Vol. XXX. No. 1. 



KEPORTS ON AN EXPLORATION OFF THE ' WEST COASTS OF MEXICO, 

 CENTRAL AND SOUTH AMERICA, AND OFF THE GALAPAGOS ISLANDS, 

 IN CHARGE OF ALEXANDER AGASSIZ, BY THE U. S. FISH COMMIS- 

 SION STEAMER ''ALBATROSS," DURING 1891, LIEUT. COMMANDER 

 Z. L. TANNER, U. S. N., COMMANDING. 



XXX. 



THE SPONGES. 



By H. V. WILSON. 



WITH TWENTY-SIX PLATES. 



[Published by Permission of Marshall McDonald and George M. Bowers, U. S. Commissioners 



of Fisli and Fisheries.] 



CAMBRIDGE, U.S.A.: 



^rinteti for tfje Puseum* 

 July, 1904. 



