THE CANADIAN ENTOMOLOGIST 



of the body indicated by narrow, smoky, cross stripes. Antennae 

 1 lack with the exception of the basal two segments and the proximal 

 extremity of segment III. A black rim borders the antennal 

 sockets. Eyes dark brown. 



Length from vertex to tip of cauda 1.6 mm. Antennae as 

 follows: Segment III, 0.4 mm.; IV, 0.256 mm.; V, 0.256 mm.; VI, 

 (0.175 mm. + 0.144 mm.). Segment III is armed with a row of 

 about 12 sensoria, which are minute and circular. Segment IV 

 is without sensoria or with 2 or 3 very minute ones. Segment V 

 has a row of about 6, while the base of segment VI has usually the 

 same number. Hind tibia 0.56 mm.; hind tarsus 0.112 mm. 



Oviparoits female. — Colour very similar indeed to that of the 

 male. The femora, however, have a distinct dusky spot near their 

 distal extremity, and the tibiae are more dusky than those of the male. 



Length from vertex to tip of cauda 1.84 mm. Antennae as 

 follows: Segment III, 0.416 mm.; IV, 0.304 mm.; V, 0.112 mm.; 

 VI, (0.176 mm. + 0.176 mm.). All segments without sensoria, 

 excepting the permanent one. Hind tibia 0.688 mm., somewhat 

 swollen and densely covered with circular, or somewhat elongated 

 sensoria. Body covered with the mushroom-like hairs described 

 in the viviparous forms. 



Described from specimens reared by the writer at East Falls 

 Church, Va., during Oct., 1916, on Carex sp. 



Type in U. S. Nat. Museum Cat. No. 20721. 



Explanation of Plates I, II and III. 



Plate 1, Fig. 1. Head of apterous viviparous form of S. americanus. 



2. Head of apterous viviparous form of S. hallii. 



3. Head of oviparous form of S. elongatus. 



4. Head of apterous viviparous form of S. flahellus. 



5. Head of apterous viviparous form of S. scirpus. 



6. Head of apterous viviparous form of S. virginiciis. 

 Plate 2, Fig. 1. View of portion of abdomen of 5. flahellus showing 



hairs. 



" " 2. View of portion of abdomen of S. americanus 

 showing hairs. 



" " 3. View of portion of abdomen of S. virginicus show- 

 ing hairs. 



