451 



Differs structurally from viridis in having the antennal joints much 

 shorter, the basal five joints of flagellum being each less than half as 

 long as the apical one, while in riridis they are much more elongate, 

 over half as long as the apical joint. 



Length, 3.75-4.25 mm. 



Type locality, Urbana, III., August 5, 1914 (C. A. Hart and J. R. 

 Malloch). Paratvpe from South Haven, Mich., July 14, 1914 (C. A. 

 Hart). 



According to the classification of other authors this species would 

 be placed, not in Chironomiis but in Orthocladins. The writer, how- 

 ever, considers that from its close resemblance structurally to viridis it 

 is more closely related to that species than to Pseitdochiroiwmiis — 

 which differs from Orthocladius (sens, lat.) only in the form of the 

 hypopygium — in which genus the use of the accepted generic charac- 

 ters would cause him to place it. 



Two females sent me by Professor Johannsen Vvhich are labeled 

 fidviventris belong to two distinct species. One of them is, I am con- 

 vinced, pseiidoviridis, but the other is in all respects in agreement wnth 

 Johannsen's description of fidviventris. The venation and leg propor- 

 tions of the latter are the same as those of viridis, but the male differs 

 from that species in color, and also in having the fore tarsi bare, as 

 stated in the original description. The locality for Professor Johann- 

 sen's specimen is Ithaca, N. Y. 



It is with considerable hesitation that I am describing this species as 

 new, but owing to the evident uncertainty that seems to exist regarding 

 the identity of fidviventris, even with its describer, and because of dis- 

 crepancies between my specimens and the original description, I can 

 take no other course. 



I have seen a large number of specimens taken at Lake Mendota 

 and Madison, Wisconsin, in June, 191 2. Most of the specimens were 

 taken from large sw^arms, the sexes occurring in different swarms. The 

 time of flight of one swarm of females is given on label as 8 p. m. 

 (A. C. Burrill). 



The Wisconsin specimens differ from the type series in having the 

 thorax shining, and in the only male which has the legs intact the fore 

 tarsi are devoid of long hairs. These hairs are readily rubbed off, and 

 as in other respects the agreement is perfect I consider them as pseiido- 

 viridis. 



31. Chironomus abbreviatus, n. sp. 



This species bears a strong resemblance to festiviis. It differs in 

 being smaller, 7.5 mm., in having the legs less distinctly browned, in 



