AQUATIC INSECTS IN NEW YORK STATD 300 
28 “Body gray with a white milky luster, specially the pleura 
and pectus. Legs tawny, femora and tibiae with irregu- 
lar piceocus bands, tarsi piceous. Length 2.5mm. Hudson 
Bay Ter.” This is a synonym of vittatum Zett. : 
according to Mr Coquillett (1898)................ ere decorum 
Thorax fuscous or cinereous pollinose, humeri pallid, pleura 
pale cinereous, scutellum pale at the tip; abdomen black- 
ish; fore coxae pale, middle and hind ones cinereous; 
femora pale at the base, black at tip; tibiae black. Length 
PPE ME ICATY: SICCIOS. oi5 sion ee es om tin ee ewe sceeewces cinereum 
29 Abdomen somewhat shining, vallowict: gray or whitish at 
the sides, and yellow at the base; legs brown, tibiae and 
fore coxae white, tip of tibiae and all tarsi black. EHuro- 
pean species, also occurring in Greenland........ Wheres, 3 reptans 
Basal segments of abdomen opaque, distal four segments! 
somewhat shining black or brown. Two long hairs at the 
Mion tie wrst ang third fore tarsal joints... 3... 6. aces ees aes (30) 
30 Legs reddish yellow, tarsi black, except proximal half of 
middle and hind metatarsi which are light yellow. Length 
2mm. (St Vincent island) This is a synonym of 
pment imm Phil. according to Hunter. ....02........2... tarsale 
Legs black, base of tibiae, first joint of middle and hind 
tarsi and sometimes base of femora yellow; extensor sur- 
face of all the tibiae more or less whitish. A widely dis- 
Poemred and. Variable SpeGieS. 0 %..c/5 aces cies wees es ences venustum 
31 Length 1.5mm. Front and middle femora and tibiae wholly 
yellow; hind ones, except apices, also yellow. (Colorado).griseum 
Length 2.5mm. (Legs brownish black, distal part of femora, 
base of tibia, and greater part of metatarsi light yellow. 
MMI IND Bere at share ete + ayaiie avin. d arabes dis dvd a die sista o © (a sste es eben argus 
Some of the characters used in this table have been taken 
from the key given in United States Department of Agriculture, 
division of entomology, bulletin 10, new series, 1898, page 68, 
by Mr Coquillett. In the table given above, I have included all 
the North American species. For the southwestern and Mex- 
ican species it should however be used with caution as I did not 
have specimens of some of these. 
Descriptions of the species 
8. argus Williston 
N. Am. Fauna, No. 7. May 1893. p.258. Cal. (Syn. of S. vittatum 
Zett. according to Coquillett, Harriman Exp. 1900.  p.898) 
Female, Black, the legs in part light yellow; front black, 
opaque; face cinereous, with whitish pubescence; antennae 
brownish black, the basal joint yellowish; thorax black, the 
