10 PAPERS OK COCCIDiE OR SCALE INSECTS. 



tion is open to anyone who wishes to study or consult it. A good deal 

 of exchange material of value has been accumulated, and exchanges 

 for sj^ecies not represented in the Department Collection will be 

 gladly made. 



A PLEA FOR THE DEPOSIT OF TYPES. 



The Coccidae present special difficulties in the way of determination 

 on account of their small size and the necessity of making careful 

 microscoj^ic preparations. Furthermore, it is not very practicable 

 to determine material from descriptions only, and it is necessary in 

 most cases to have type, or accurately identified material, for the pur- 

 pose of comparison. With Coccidse, therefore, more than with other 

 groups of insects, it seems necessary to have some central depot for 

 the deposit of types, where authoritative identifications may be made. 

 It is hoped and urged, therefore, that all American describers of new 

 species will adopt the course of placing type or cotype material in 

 the National Collection, where it will be carefully preserved and be 

 available for study at any time. 



O 



