16 DIPTERA 



I. Genus JANTHINOSOMA, Arribalzaga* 



Janthinosoma. Arribalzaga. Dipt. Argent, p. 52 (1891). 



Characters. — Head covered with rather broad spindle-shaped scales and upright forked ones 

 Thorax with short, broad spindle- shaped scales and also the scutellum. Male palpi long, longer than 

 the proboscis, both tf and 9 palps densely scaly. Hind legs always densely scaly, giving the insects 

 a characteristic appearance, one or more of the hind tarsi always white ; ungues of 9 very thick, 

 uniserrated, fore and mid in the cf unequal, serrated. 



They are all somewhat metallic when fresh. 



Geographical distribution of species. — So far this genus has only been found in South 

 America, the West Indes and the South of North America. Five species are known. 



1. J. musica, Say, Journ. Acad. Nat. Sc. Philad. Vol. 6, p. 149 (South America, Trinidad, Indiana). — 



Plate I, Fig. 9. 



Culex musicus. Say. 

 mexicanus, Bellardi. 



2. J. fiosticata, Wiedemann, Aussereurop. Zweifi. Ins. p. 9 and Dipt. Exot. Vol. 1, p. 43.2 (1828) 



(St Lucia, Argentine). 



Culex posticatus, Wiedemann. 



3. J. lutzii, Theobald, Mon. Culic. Vol. 1, p. 257 (1901) (Brazil, British Guiana, Trinidad). 



4. J. discrucians, Walker, Ins. Saund. p. 140(1856) (South America (Walker); Trinidad). 



Culex discrucians, Walker. 



non J. discrucians, Arribalzaga. 



5. J. arribalzaga, Giles, Hdb. of Gnats. 2 d ed. p. 341 (Brazil, Argentine). 



discrucians, Arribalzaga, Dipt. Arg. p. 53 (i855). 



6. J. varices, Coquillett, Canad. Ent. p. 10 (1904) (Fort Simpson, B. C. Canada). 



Conchyliastes varipes, Coquillett. 



2. Genus PSOROPHORA. Robineau-Desvoidy 



Psorophora. Robineau-Desvoidy, Essai Culic. p. 412 (1827). 



Characters. — Head covered with small broad curved scales and upright forked ones; meso- 

 thorax with curved scales in the middle and short broad ones lateralby. Palpi long in the <~/,of 5 segments, 

 longer than the proboscis ; in the 9 short, never more than half the length of the proboscis, composed 

 of four segments (? 5). Proboscis short and thick in the <-f ; longer and bent in the 9 • Prothoracic lobes 

 have appendages which protect the stigmata of that area. Legs with the apices of the femora and tibiae 

 and to some extent the metatarsi with long scales; ungues of 9 thick, equal uniserrated. Wings with 

 rather long thin lateral vein-scales; first submarginal only a little longer than the second posterior cell; 

 posterior cross-vein close to the mid but usually a little nearer the base of the wing than the mid. 



This genus can at once be told by the arrangement of the thoracic scales, and the densely 

 scaled legs. 



Geographical distribution of species. — So far as at present known this genus is confined to 



North and South America and the West Indes. 



1. P. ciliata, Fabricius, Ent. Syst. Vol. 4, p. 401 (1794) (North America and Brazil). — Plate I, Fig. 8. 

 perterr.ens. Walker, Ins. Saund, p. 431 (iS56). 

 boscii, Robineau-Desvoidy. Essai Culic. p. 413 (1827). 

 molestus, Wiedemann, Dipt. Exot. Vol. 7, p. 4 (1S21). 

 centaurus, Walker, Brit. Mus. Coll. (Ms. name). 



* Howard and Coquillett, place these insects in a genus Conchyliastes, a ms term used by me before I had fixed the genus but never 

 published — there is no such genus. 



