

Bulletin of the, Museum of Comparative Zoology, 

 AT HARVARD COLLEGE. 



Vol. XVIII. 



REPORTS ON THE RESULTS OF DREDGING, UNDER THE SUPER- 

 VISION OF ALEXANDER AGASSIZ, IN THE GULF OF MEXICO 

 (1877-78) AND IN THE CARIBBEAN SEA (1879-80), BY THE U. S. 

 COAST SURVEY STEAMER "BLAKE," LIEUT.-COMMANDER C. D. 

 SIGSBEE, U. S. N., AND COMMANDER J. R. BARTLETT, U. S. N., 

 COMMANDING. 



[Published by Permission of Carlilk P Patterson and J. E. Hilgard, 

 Superintendents of the U. S. Coast and Geodetic Survey.] 



XXIX. — REPORT ON THE MOLLUSCA. 



By W. II. DALL. 



PART II. — GASTROPODA AND SCAPHOPODA. 



With Thikty-onk Plates. 



CAMBRIDGE: 



PRINTED FOR THE MUSEUM. 



June, 1889. 



