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MUSEUM OF COMPARATIVE ZOOLOGY. [Apr. 



During the spring, however, considerable labor was devoted 

 to them. Several groups were carefully niounted on tablets, 

 all the specimens accompanied by labels having been closely com- 

 pared with original descriptions or with the earliest figures, 

 such as bore no names but belonged to described species having 

 been critically identified, and such as belonged to undescribed 

 species put into a condition to be named or described at leisure. 

 The remaining Tertiary Gasteropods are also, to a large extent, 

 ready, as fast as they can be revised with discrimination, to be 

 mounted and placed on exhibition. In many parts of this labor 

 I i^ieceived valuable assistance from Miss Annie Cutler. 



The fossil Corals have likewise received some attention. 

 Many have been cleaned and numbered, while increased prepara- 

 tion has been made for the mounting of the whole collection on 

 tablets. In this work, and in various other ways, 1 have been 

 aided by Miss Atkinson. 



The course of instruction on the Geology of Massachusetts, 

 began during the preceding autumn, was duly completed in the 

 winter term, extending to thirty-six lectures. 



The vast palseontological stores of the Museum having been 

 intrusted to my care by the Director, it was found convenient to 

 divide them, at the start, into three portions, all of the Palae- 

 ozoic age going into the first, those of the Secondary or 

 Mesozoic age, into the second, and those of the Tertiary or 

 Cainozoic age, into the third, each portion being destined for a 

 separate room. Accordingly, it has been the aim, as separations 

 have been made, to convey, with a few slight exceptions, all the 

 Tertiary animal remains to the Cainozoic or Recent room, all 

 the Secondary to the Mesozoic, and all ttte older to the 

 Palseozoic. The Tertiary fossils being, in numerical proportion, 

 predominantly Mollusca, occupy a room in connection with the 

 recent Mollusca, for convenience of comparison. 



In addition to this separation of fossils, according to age, sub- 

 divisions have been attempted in each room. For instance, the 

 Palasozoic remains are primarily divided into three general 

 sections, accordingly as they belong : 1st, to the Taconic ; 2d, to 

 the Silurian ; and 3d, to the Devonian, Carboniferous or Per- 

 mian ; the exact time of demarcation between the latter forma- 

 tions not being as yet clearly defined. The Museum fossils, 

 however, belonging to the later Palaeozoic times have been 



