230 ENTOMOLOGICAL NJEWS [July, '24 ENTOMOLOGICAL NEWS, containing the description of Klon-eus babayaga, was mailed at the post-office at Philadelphia, May 4, 1923. The type of Obcrthurion harrovcrii Clark was borrowed for study and description by B. Preston Clark, September 25. 1922, and has not been returned to the Academy of Natural Sciences of Philadelphia. The Occurrence of Nygmata in the Wings of Insecta Holometabola. By WM. T. M. FORBES, Ithaca, New York. (Plale V.) It is well known that the majority of Trichoptera possess two small, apparently glandular spots on the wings, one located in the base of cell R4, and the other, somewhat less universally in cell M. Navas has christened these structures "nigmas," according to the reformed spelling of Spanish. In English we should follow the spelling of the Greek word and call them "nygmata" (singular "nygma"). The word means merely a spot or puncture, and that is all that is really known of them. On account of their presence near the center of the wing, and tendency to be absent in small species, one may suspect them of being moulting fluid glands for the imaginal moult, but I believe there is no evidence whatever on the case. Finding that essentially the same structures are also present in the sawflies, I made a systematic search of the principal groups of insects, with the following result. Nygmata are present in a large proportion of species of the Neuroptera (including the Planipennia), Trichoptera, Panor-pata, and the Chalastogastrous Hymenoptera. They are absent in all the Hemimetabola examined, and also in the Lepidoptera and Diptera. They are also absent from the wings of Coleop-tera, but the question may be raised if some of the various structures on the elytra of Coleoptera may not be homologous. The position of the nygmata is definite in any one group, but occasionally they are present or absent in closely related forms, especially in the Hymenoptera, where they are frequently weakly developed. The various families of an order have simi-
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