432 NEW YORK STATE MUSEUM 



2 Knob of the halteres black. With the head, iDalpi, base of the 



antennae, thorax, venter and the legs except the tip of the 

 femora, yellow. Length 2.7mm. Berl. Ent. Zeit. 1863. 



Centur. 3, p.l. District of Columbia marginata Loew 



Knob of the halteres yellow. With the head, antennae, palpi 

 (except the base), thoracic stripes and part of the legs 

 brown or black (3) 



3 Cross vein with cloud. " The peduncle of veins Ki and R2 



very short." Female. Length 2.7mm. Berl. Ent. Zeit. 

 1863. Centur. 3, p.4. Maryland and New Jersey (John- 

 son) notata Loew 



Cl'oss vein not clouded. Peduncle of this vein as usual; a 

 little shorter in the male than in female. Length 2.5mm. 

 Berl. Ent. Zeit. 1SG3. Centur. 3, p.3. New York and 

 Ithaca N. Y. (=? D. r e c e n s Walker) t e r n a Loew 



4 Species having both the proboscis and the knob of the halteres 



black (5) 



Having proboscis and halteres of different colors (6) 



5 Thorax with yellow space between the dark dorsal stripes. 



Ithaca N. Y m o d e 3 t a 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- 

 tur. 3, p. 5. New York fusca Loew 



6 Wiih 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.l. Texas.venosa Loew 

 With black proboscis; halteres yellowish; palpi and proboscis 



and tips of femora and tibia black (7) 



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. 1863. Centur. 



3, p.3. New York, (=D. nova 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. 

 8, p.l. Massachusetts clavata Loew 



Family chiro?<oaiidab 



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 



