62 Report of the President 



time to devote to the more critical study of the collections, 

 and were it not for the cordial cooperation of outsiders but 

 little progress could have been made in rendering them of 

 greater scientific value. There are more than one million 

 specimens of all species in the charge of officers of their 

 divisions, and many of these may be made of far greater 

 scientific interest through their adequate study when this may 

 become possible. Naturally, the preliminary work noted 

 above is the first essential. One of the most important phases 

 of the year's work has been the careful cataloging and labeling 

 of type specimens; more than 1,700 species of insects are 

 represented either by types or by cotypes. 



Three large groups have been placed on exhibition in the 

 Hall of Insects. One of these shows a swarm of migratory 

 butterflies (Danais plexippus) resting on a small oak tree; 

 another illustrates more than a dozen distinct features of the 

 biology of the periodic Cicada (Tibicen septendecini) ; while the 

 third is a reproduction of a nest of the mound building ant 

 (Formica exsectoides) showing about four hundred insects at 

 work. These groups show a notable advance upon the usual 

 methods of exhibiting insects through the adaptation of means 

 earlier employed for the exhibition of birds and mammals. By 

 reason of the small size of insects it is possible to display large 

 numbers of individuals within an area of a few square inches 

 in a setting which reproduces their natural surroundings; they 

 are very useful in fixing the interest of visitors and thus 

 inducing them to read the labels which explain the scientific 

 points illustrated by the exhibits. 



Molluscs. — During the year the collections have been en- 

 larged by certain items which will doubtless repay closer 

 study. Arthur D. Gabay has continued his gifts of attractive 

 material which, with that acquired in former years, might be 

 incorporated in an exhibit illustrating the ornamental uses of 

 shells. The collections of the genus Cerion, already consider- 

 able, have been amplified by the material collected during the 

 year in the Bahama Islands by the Curator. 



The collection of shells is now safely housed in iron cases 

 provided for its permanent installation in the new Hall of 



