432 NEW YOUK STATE MUSEUM 



2 Knob of the lialteres black. With the head, palpi, base of the 



auteuuae, thorax, veuter and the legs except the tip of the 

 femora, yellow. Length 2.7mni. Berl. Ent. Zelt. 1863. 



Ceutur. o, p.l. District of Columbia marginata Loew 



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

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

 brown or black (3> 



3 Cross vein with cloud. " The peduncle of veins IJ^ and Rg 



vegy . '^^ ^jmCTT^ Female. Length 2.7mm. Berl. Ent. Zeii. 

 1803. Centur. 3, p.4. Maryland and New Jersey (.John- 

 son) •,^,• •■ Ji/O t a t a Loew 



Cross vein not clouded. Peduncle of this vein ac uot t a l, a 

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

 Berl. Ent. Zeit. 1863. Centur. 3, p.3. New York and 

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



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



black (5) 



Having jjroboscis and halteres of different colors (6> 



5 Thorax with yellow space between the dark dorsal §,tripeSj, /^^t^t 



Ithaca N. Y in niirnfiWT. 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. Zlet. 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. 

 S, p.l. Massachusetts clavata Loew 



Family chironomidae 



This family is exceedingly rich in species. Owing to the fact 

 that the life history of comparatively few is known, it is diflS- 

 cult to give a key even to the genera of the larvae and pnpae. 

 The Chironomidae may be divided into three gronps, the first 



