REPORT OF THE SECRETARY. 31 



erly done by one intimately acquainted with the entire subject. 

 Dr. Loew has found, for instance, that a genus (Paralimna Fab. 

 Hydromysidae) occurring in North America, and foreign to Europe, 

 had been also discovered in Africa, and previously described. Al- 

 most any one but Dr. Loew would have formed a neio genus of this 

 insect, and the interesting fact of the occurrence of the same 

 genus in Africa and America, and not in Europe, Avould have been, 

 for a time at least, unknown to science. Some other curious re- 

 sults have been obtained by this naturalist from the study of Baron 

 Osten Sacken's collections. A species of horhorus, from Cuba, has 

 been found identical with an African species, and from tlie matter on 

 which this fly occurs (alvine dejections) it is probable that it has been 

 accidentally imported into that island by a slave ship. A still more 

 interesting result is the discovery of the striking analogy between 

 the present American and the fossil tertiary fauna, coinciding with 

 the analogy of the corresponding floras. Dr. Loew having mono- 

 graphed the fossil Diptera preserved in Prussian amber, and having 

 described no fewer than 656 of such species, was better able than 

 any one else to trace this analogy. The remarkable fact appears 

 from his investigation that insects, some of them very singular, which 

 are absolutely extinct in Europe, are now found living in America. 



Such have been, up to the present time, the entomological publi- 

 cations of the Smithsonian Institution. They do not as yet embrace 

 the three orders of Hemiptera, OrthojJtera, and Hymenoptera. Mr. 

 Ph. E. Uhler, of Baltimore, who has for several years made the North 

 American Hemiptera (tree bugs, plant lice, &c.,) the special subject of 

 his study, is preparing for the Institution a work in regard to these 

 insects on the same plan as that of Hagen's Neuroptera, which it is 

 expected will be soon ready for publication. 



Little has yet been done for the Orthojitera, (grasshoppers, rear 

 horses, crickets, <fec.,) although, owing to the small extent of this 

 order, it would be a comparatively easy task to produce a work similar 

 to the synopsis of Neuroptera, if a suflScient collection of specimens 

 were in existence. The Institution has adopted measures to have 

 this desideratum supplied. The study of North American Hij- 

 menoptera (bees, wasps, &c.,) was undertaken several years ago by 

 Mr. H. de Saussure in Geneva, and large collections have been fur- 

 nished to him by the Institution. It is expected that his manuscript 

 will soon be furnished for publication. 



