526 



rows of setae ; nietathoracic wing-cases extending caudad to the middle 

 of the fourth abdominal segment. 



Abdomen long and slender, uniform buff, the cuticle provided 

 witli minute setae; segments 3—10 with dorsal tr.uisverse rows of setae 

 at the caudal margins and segments ^-/ with similar ventral rows, the 

 setae grouped somewhat conspicuously 1 >n the meson ; lateral keels 

 strongly developed, setose, the keel of the first segment with a number 

 of heavy setae, usually three, tiiat of ih.e second with a row of eight or 

 nine, and keels of the third to the eighth segments with a row of ten or 

 twelve, and with groups of two or three at the apices ; ninth segment 

 with a lateral row of setae in line with tjie lateral keels; gills (Fig. 80) 

 ^•ery long, somewhat spatulate, the points mostly blunt. ;md the dorsal 

 iiiarginal row of setae of the meilian gill extending much beyond the 

 middle ; three narrow transverse bands .sometimes occur just beyond 

 the middle; they are placed closely together as a rule, l)ut the bands 

 may be reduced to one or may be wantmg. 



Measiu'cv^ents 



Length 15 mm. 



Length of abdomen 9 mm. 



Length of gills 7 mm. 



Width of gills 1.8 mm. 



Length of median lube 2.3 mm. 



Width of median lobe 8-1.6 mm. 



Described from three specimens in the collection of the State 

 Laboratorv of Natural Histurv, collected at Havana, 111., Tune 30, 

 1897. 



The nymph has not been reared, but the specimens were deter- 

 mined from a description given by W;dkcr. 



/hhilf; Male. — Color, blue and black. 



Head blue and black, buff below; laljium i)uff, the median lobe 

 subtriangular, the apical cleft narrow ; distal segment of the labial palpi 

 pale; postclypeus black except the lateral margins. ;mteclypeus, l.abrum, 

 mandibles, their trochantins, genae, and the transverse area above the 

 dypeus blue ; lateral ocelli with a small blue spot cejihalad of each, the 

 remainder of the front and vertex black ; jiale line caudad of the ocellar 

 area distinct, the ends narrowly separated from the large blue, cunei- 

 form postocular spots; occiput pale except a transverse black line bor- 

 dering the postocular spots. 



Thorax blue and black ; pronotum mostly black, with a large blue 

 spot on eacli median lobe, the caudal margin df the caudal lobe and 



