ENALLAGMA 325 
311. Enallagma piscinarium Williamson 
Wmosn. ’00, p. 273: Mtk. Cat. p. 61. 
Length 28 mm. Expanse 34 mm. N.Y, Ns Js, a. 0G: 
One of the rarer blue and black Enallagmas found around fish ponds. The 
following description of the male is taken from Mr. E. B. Williamson’s original 
one: ‘‘Head blue, beneath pale. Vertex, antennae (except the first joint), and 
the postclypeus, black. Postocular spots rounded, cuneiform, narrowly con- 
nected. Prothorax black, posterior lobe narrowly margined with blue. Thorax 
blue, a middorsal and a humeral stripe and a spot on the second and third lateral 
sutures just under the wing bases, black. Abdomen blue, black as follows: 
a basal spot and a narrow apical ring on 1; an apical spot connected with an 
apical spot connected with an apical ring on 2; very narrowly interrupted basal 
rings on 3—6 (these rings are wider anteriorly becoming narrower successively) ; 
all of 7 and 10. Sides of 1 and 2 blue, posteriorly the black of the dorsum extend- 
ing more unto the sides.’’ Superior appendages very similar to E. geminatum. 
Male. 
312. Enallagma durum Hagen 
Hag. 61, p. 87: Mtk. Cat. p. 58: Wmsn. ’22, p. 142: Root ’23, p. 202: Garm. ’27, 
p. 83. 
Length 32-38 mm. Expanse 48-52 mm. Mass., R. I., to Fla. and La. 
One of our largest bluets, frequently recorded from brackish water ponds. 
Colors, blue and black. Head typical of the blue-black Enallagmas, postocular 
spots usually united. Prothorax and thorax not differing from those of this 
group already described, except that the middorsal carina is yellow or blue 
1) Te Ty 
cyathigerum piscinarium durum minusculum 

separating the middorsal black stripe into two parts. Wings with 4-5 antenodal 
cells. Abdomen blue with the following black: a basal spot on 1, wider than 
long; a rounded apical spot with an apical “‘tail’’ on 2; apical part of 3-6, pointed 
anteriorly; all of 7, except a transverse basal ring; the dorsum of 10. 8-9 blue. 
Superior appendages one-fourth to one-third as long as 10, excavated within, but 
not bifid, inferior apical angle with a small tubercle. Inferior appendages a little 
longer than the superior. 
Female. Color, yellowish-red and black. Similar to the male in the head 
and thorax. Dorsum of 1-9 with a broad black band widened before the apices, 
and interrupted transverse basal yellow rings on 3-7. Dorsum of 10 mostly pale. 
313. Enallagma minusculum Morse 
Morse ’95, p. 207: Mtk. Cat. p. 60: Howe ’17, p. 16: Garm. ’27, p. 77. 
Length 26 mm. Expanse 34 mm. Mass. and N. H. 
A rare species very muchly circumscribed in its range. Described by Dr. 
Morse as follows: ‘‘Cuneiform postocular spots small, more or less rounded. 
