432 NEW YORK STATE MUSEUM 
2 Knob of the halteres black. With the head, palpi, base of the 
antennae, thorax, venter and the legs except the tip of the 
femora, yellow. Length 2.7mm. Berl. Ent. Zeit. 1863. 
Centurso, pl. - District of (Columbia. a2 sass ae marginata Loew 
Knob of the halteres yellow. With the head, antennae, palpi 
(except the base), thoracic stripes and part of the legs 
brown or Dlack. . . ee sae So ne bo na ci wore nbs wee oyc.6 oS ene (3) 
Cross vein with cloud. ‘“‘ The peduncle of veins R; and Re 
very short.’ Female. Length 2.7mm. Berl. Ent. Zeit. 
1863. Centur. 3, p.4. Maryland and New Jersey (John- 
SOD) Sek: . Bek ck ORR ENG «elas Se ete ee notata Loew 
Cross vein not clouded. Peduncle of this vein as usual; a 
little shorter in the male than in female. Length 2.5mm. 
Berl. HEnt. Zeit. 1863. Centur. 3, p.38. New York and 
OO 
Tthaea. N;. ¥é (23D: neces Walker)... 00a eee terna Loew 
4 Species having both the proboscis and the knob of the halteres 
POTAGK: o srese F ciaye,g ioren chee ovepa & oe aw ane Gg Sh cpelle, gece oye salete eee ar (5) 
Having proboscis and halteres of different colors. ...... 22. 0e eee (6) 
5 Thorax with yellow space between the dark dorsal stripes. 
Mapa a, ING NE Se ewan na oie Oo late ie hottee ee ie sae eee eee modesta n.sp. 
Without yellow on dorsum. Blackish species. Lower part of 
the pleura, sometimes scutellum and metanotum, coxae and 
base of the femora, and stem of the halteres yellow. Male 
and female. Length 2.5 mm. Berl. Ent. Zeit. 1863. Cen- 
Utes po. New Yorkie inten oh oes ol oe eee ee fusca Loew 
6 With yellow rostrum; halteres with a fuscous head. Head, 
palpi, antennae, thoracic and pleural stripe, abdomen and 
tip of femora wholly black; tarsi fuscous. Length 3 mm. 
Male. Berl. Ent. Zeit. 1872. Centur. 10, p.1. Texas.venosa Loew 
With black proboscis; halteres yellowish; palpi and proboscis 
and tips of femora and tibia, DICK oc... 6 ie tcese cin c.clae ee eee ee (7) 
Antennae and _ scutellum black; pleura and metanotum . 
black; and tarsi and abdomen fuscous black; halteres sor- 
didly yellow. Male 2.7 mm. Berl. Ent. Ziet. 18638. Centur. 
3, p.3o. New York, (=D. noya Walker?)........ centralis Loew 
Antennae yellow at the base, flagellum pale fuscous, scutel- 
lum fuscous testaceous; tip of posterior tibiae thickened. 
Metanotum black with yellow margin; abdomen shining 
cinereous black; tarsi black toward the tip. Male and 
female. Length 4.2 mm. Berl. Ent. Zeit. 1869. Centur. 
B, upd. Massachusetts... 04 ats eats ene sete ete ee clavata Loew 
=I 
Family CHIRONOMIDAE 
This family is exceedingly rich in species. Owing to the fact 
that the life history of comparatively few is known, it is diffi- 
cult to give a key even to the genera of the larvae and pupae. 
The Chironomidae may be divided into three groups, the first 
