— io6 — 



piled, and be abundantly illustrated with colored figures. Work with 

 this object in view was steadily continued for a time. Prof. Riley and I 

 worked as well as we couUi apart, on the lines agreed upon between us, 

 and a great lot of manuscript was gradually accumulated which it was 

 intended should be worked up and completed when we could get at the 

 labor together. 



The opportunity for this closer co-laboration seemed to offer when 

 I became Assistant Curator in the Department of Insects of the U. S. 

 National Museum at Washington, but I soon found myself fully em- 

 ployed otherwisf, and Prof. Riley, what with ill health and his numerous 

 other duties, found less and less time to give to the conjoint work, so 

 that the monogra|)h originally proposed was never completed. Aside 

 from these C(in>iderations, other influences helped to dampen our ardor 

 in prosecuting the work to final issue. One was Prof. Riley's excessive 

 caution and the desire of getting at a/l ihe information known and un- 

 known concerning a species, which tended to check rapid work, the 

 other the difficulty, if not impossibility, of getting a sufficient appro- 

 priation for the publication of a monograph so elaborately illustrated as 

 we had planned this should be. 



I found time iiowever, in the midst of other work to prepare a 

 number of descriptions, and to make use of the excellent library facilities 

 at hand, and accumulated a great lot of material of use when systematic 

 work should again become possible. When, recently, I accepted the 

 position of Professor of Entomology at Rutgers College and Entomo- 

 logist to the Agricultural Experiment Station of New^ Jersey, it was 

 agreed between Piot. Riley and myself that the joint work as originally 

 plataned should be abandoned, and that, while mutual co-operation 

 should continue, the results should be publishetl jis most convenient. 

 It was realized that the fauna is not yet sufficientl)' known to enable a 

 work to be carried on (or several years vviihoui antiquating the beginning 

 before the end was reacheil, as new material from new regions was con- 

 stantly turning up. In consequence I shall, under the title of this paper, 

 and ihe sub-iitle of the pait:cular genus or group treated, publish as fast 

 as thev can be revised, the studies made by me on the NuciiddcB, omitting 

 only certain special groups and genera which Prof Riley has more par- 

 ticularly worked upon. No particular order will be observed, and no 

 one publication will be selected for all the papers, but so far as possible 

 each paper will be complete in itself, save when special considerations 

 render advance publications of fragments desirable. The material npon 

 which these studies are made is principally in the National Museum, 

 but Messrs. Hy. Edwards, E. L. Graef, Geo. D. Hulst, B. Neumoegen, 

 Fred. Tepper, A. W. P. Cramer, J. Doll, Geo. Frank, and many others 



