. Biology of the Membracidae of the Cayuga Lake basin ... Membracidae. Biology of the Membracidae of the Cayuga Lake Basin 313 other types of development are built, and is apparently one of the most generalized of the prothoracic processes. It may vary from a perfectly simple short prong to a long, ornate projection often branched and extravagantly decorated with barbs, spines, bulbs, and ridges (fig. 40). So constant and so important is this posterior process that it has been made the character on which the subfamily Centrotinae is separated. All forms that have the posterior process wanting
. Biology of the Membracidae of the Cayuga Lake basin ... Membracidae. Biology of the Membracidae of the Cayuga Lake Basin 313 other types of development are built, and is apparently one of the most generalized of the prothoracic processes. It may vary from a perfectly simple short prong to a long, ornate projection often branched and extravagantly decorated with barbs, spines, bulbs, and ridges (fig. 40). So constant and so important is this posterior process that it has been made the character on which the subfamily Centrotinae is separated. All forms that have the posterior process wanting or so poorly developed that the scutellum is distinct — and it would seem that the development of the scutellum increases as that of the posterior process decreases — have been placed in this subfamily, which as a result has received a rather heterogeneous collection of genera (Fowler, 1894-97). In generic and specific diagnoses the pronotal structures have been more generally used than any other characters shown in the family. This is to be expected, from the fact that they are prominent and quickly noted. Moreover, they are on the whole reliable and of much value. In the use of such characters, various areas and processes have received p,^ 4^3 ^.^^^^,^ development of pos- arbitrary names, which, while of terior process Httle anatomical significance, are of ^''^^^^'^ Bastm) assistance in making uniform the terminolog}^ used by systematic workers in the family. A few of these are deserving of special mention. Metopidiuin (fig. 41, a) is a term originated by Fowler (1894-97:1) and commonly used by later authors (Van Duzee, 1908 a:30) to designate that area of the cephalic part of the pronotum reaching from the dorsum to the base of the head. The humeral angles (fig. 41, b) are the swelhngs, very characteristic of the family, found on the lateral margins of the prothorax usually just above the bases of the forewings. The suprahumerals, or siiprahumeral horns (fig. 41, c), are
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Keywords: ., bookcentury1900, bookdecade1910, bookpublisherithacany, bookyear1
