. Bulletin - New York State Museum. Science. 252 NEW YORK STATE MUSEUM been studied and collected suflScientlv for the determination of this matter. It would be utterly impossible at present to give a key that would distinguish females, and a key for the males based on coloration would have to be offered tentatively, since the range of variability in color pattern has not been determined. Instead of attempting a key, I have thought best to present herewith drawings of the appendages of the male of all species known from the f^tate, these being the surest criteria for the recognition of the spe
. Bulletin - New York State Museum. Science. 252 NEW YORK STATE MUSEUM been studied and collected suflScientlv for the determination of this matter. It would be utterly impossible at present to give a key that would distinguish females, and a key for the males based on coloration would have to be offered tentatively, since the range of variability in color pattern has not been determined. Instead of attempting a key, I have thought best to present herewith drawings of the appendages of the male of all species known from the f^tate, these being the surest criteria for the recognition of the species. The males can then be determined by comparison with the figures, and the females can be kept with the males with which they are found associated in nature. As is to be expected in such a genus, the nymphs are very much alike. A brief general description here will therefore save much repetition in treating of the species. Nymph. The nymph of Enallagma is slender, nearly smooth,. with the head a third wider than succeeding parts of the body (the excess of width being wholl}- due to the lateral prominence of the eyes)^ and with abdomen very slightly taper- ing posteriorly. The head is one half wider than long, with frons moder- ately prominent, broadly rounded hind angles, and a wide posterior excava- tion between them. Antennae long, slender, seven jointed, the segments increasing in length to the third, and decreasing thereafter to the tip. Legs slender, nearly smooth, often banded with brown. Wing cases reach pos- teriorly to the middle of the fourth abdominal segment. Abdomen cylin- dric, its segments decreasing a very little both in length and in diameter toward the apex. Gills lanceolate^ pointed, with variable color pattern. Labium slender, with prominent median lobe, lateral lobes upcurved at their external margins; mental setae Lateral setae four to five each side. Lateral lobe with a moderate movable hook and an arcuate end hook and several small teeth on the dista
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectscience, bookyear1887
