DEPARTMENT OF MOLLUSKS. 



167 



Unios, though printed, will be issued a few days too late to appear in 

 the Bibliography of this year. The priucipal labor of the year has been 

 bestowed on the continuation of the report on the Florida Tertiary Mol- 

 lusks, for the Wagner Institute, of Philadelphia; preliminary work on 

 the mollusks of the Galapagos trip of the IT. S. Fish Commission 

 steamer Albatross, and also those collected by Dr. G. Baur; and on the 

 Unionida', to which group Mr. Simpson is giving special attention. 



STATE OF THE COLLECTION. 



In previous reports I have explained why it is not yet possible to 

 give the exact number of species, specimens, duplicates, etc., contained 

 in the collection under my charge. In my last report it was estimated 

 that the collection contained about 470,500 specimens, of which one- 

 fourth are preserved in alcohol. During the year about 0,225 speci- 

 mens have been received, which would make a present total of about 

 482,725 specimens contained in the collection. The number of entries 

 in the register for 1891-'92 was 2,540, as is shown in the accompanying 

 table. 



The total number of registrations to date, deducting all duplications 

 and omissions in the register, is 103,113, representing about 300,000 

 specimens. The number of workers and their distribution in different 

 parts of the building renders it necessary to use simultaneously several 

 volumes of the register. This explains why the preceding' table is nec- 

 essary in order to show the total registrations for the year. The formal 

 registrations (with the gaps alluded to) terminates June 30, 1892, with 

 number 124,002. 



