GENUS JANTHINOSOMA 341 



amethystine and black, dorsally unadorned, but the segments 

 beautifully marked on the venter with golden triangular apical 

 spots and amethystine basal areas. 



A beautifully brilliant insect when in good condition, wliich may at 

 once be known by its long, thick-scaled, hind legs, with white tarsi as 

 described. 



Head with sooty ground colour clothed with deep golden ferruginous 

 short falciform scales, and erect forked ones of a somewhat deeper shade. 

 Palpi, 5 , short, deep purple at apex, with a golden tinge at the base. 

 Antennae dusky. Legs with all the femora pollen yellow at the base, 

 most extensively so on the hind pair ; the joints from the tibia down- 

 wards greatly enhanced in apparent breadth by a dense covering of long 

 scales. Length. — 4-8 to 5 mm. 



Habitat. — Rio de Janeiro; British Guiana; Indiana; South Amazon. 



Time of capttire. — Rio de Janeiro, November (Moreira). 



Observations. — This seems to be an abundant South American species, 

 which Dr. Lutz calls the Big Wood Mosquito. It stings, says Dr. Lutz, 

 in the daytime. 



4. JANTHINOSOMA POSTICATA (Wied.) (" A. Z. I." p. 9). 



"Wings unspotted, dusky. Tarsi uniformly dark bronzy, 

 except the last joint of hind legs, which is entirely white. 

 Thorax dark brown, unadorned, but clothed with short falciform, 

 golden scales. Abdomen deep chocolate-brown, unhanded, but 

 adorned with an ill-defined triangular golden spot on the tergum 

 of the second, and with large, triangular lateral spots on the 

 hinder borders of each segment, which latter, however, are scarcely 

 noticeable viewed directly from above, venter entirely yellow but 

 for a row of small, triangular dark basal spots. 



5 . — Head black grounded, with forked scales and short falciform 

 scales alike of a golden tint. Antennae fuscous, about half the length of 

 proboscis. Palpi very short, of a uniformly dark metallic purple. 



Pleurae marbled with white and golden ; femora yellow beneath, but 

 seen from above are but little paler at base than at apex ; there are no 

 knee-spots beyond a faint paling of tlieir apices. The tibiae, especially of 

 the hind legs, appear apically dilated owing to their dense covering of 

 long scales. Halteres with pale stem and fuscous knob. Length. — 

 5 mm. 



Habitat. — Castries, St. Lucia ; Argentina. 



5. JANTHINOSOMA ARRIBALZAG^, Sp. n. 



Janthinosoma discrucians, Arribal. (" L. A." p. 53). 

 Plate xiii, fig. 2a, Venation of wing, J ; 2b, Tarsus of hind leg. 

 Wings unspotted, densely black-scaled ; unusually wide in 

 proportion to their length. Tarsi uniformly black- Scaled, with 



