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Bulletin of the Museum of Comparative Zoölogy 

 AT HARVARD COLLEGE. 



Vol. XXV. No. 10. 



REPORTS ON THE DREDGING OPERATIONS OFF THE WEST COAST OF 

 CENTRAL AMEKICA TO THE GALAPAGOS, TO THE WEST COAST 

 OF MEXICO, AND IN THE GULF OF CALIFORNIA. IN CHARGE OF 

 ALEXANDER AGASSIZ, CARRIED ON BY THE U. S. FISH COMMIS- 

 SION STEAÄIER "ALBATROSS," DURING 1891, LIEUT. COMMANDER 

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



XIII. 

 DIE OPISTHOBRANCHIEN. 



Von Rudolph Bergh. 



[Published by Permission of Marshall McDonald, U. S. Fish Commissioner.] 



WiTH Twelve Plates. 



CAMBRIDGE, MASS., U. S. A. : 

 FRINTED FÜR THE MUSEUM. 



OCTOBER, 1894. 



