558 MOSQUITOES or north AMERICA 



Obiginai, Descriptiois" of Janthixosoma lutzii: 



Thorax black, with flat spindle-shaped bronzy-black scales in the middle and flat 

 spindle-shaped creamy-yellow ones forming a broad line on each side of the meso- 

 notum. Abdomen brilliant blue and purple, an apical yellow patch extending nearly 

 across each side of the segment and pale golden ventral bands. Legs metallic purple, 

 bases of the femora broadly pale yellowish; last two joints and apex of the ante- 

 penultimate tarsi of the hind legs white. 



$. Head clothed in the middle with curved and small flat irregular golden scales 

 and ochraceous upright forked ones, purple at the sides; palpi and proboscis brown, 

 with brilliant metallic purple reflections; antennae brown. 



Thorax black, with black and bronzy spindle-shaped scales, each side of the meso- 

 notum with golden-yellow spindle-shaped scales forming broad yellow lateral bands 

 with straight borders to the median dark area; scutellum dark brown, with small 

 bronzy-black spindle-shaped scales; metanotum black; pleurae dark brown, with 

 creamy-yellow flat scales. 



Abdomen steely-black, covered with brilliant metallic blue and purple scales, be- 

 coming dusky towards its apex, with lateral apical golden patches to the segments, 

 more or less triangular in form, the base of the triangles being parallel to the apical 

 borders of the segments; first segment dark, with dusky scales and long golden-brown 

 hairs; venter purplish, with golden scaled apical cross-bands. 



Legs metallic purple in some lights, brown in others; coxae dark with yellow 

 scales; fore and mid femora yellowish at the base below, hind femora with a broad 

 yellow basal portion; knee spot pale; last two tarsi of the hind legs creamy-white, 

 also the apex of the antepenultimate joint; ungues of the fore and mid legs uni- 

 serrated. 



Wings with a brownish tinge; veins clothed with brown scales, those at the base of 

 the wing with purple reflections; lateral scales long, rather broader than in Culex, 

 apices convex; first sub-marginal cell longer and narrower than the second posterior 

 cell, its base nearer the base of the wing; its stem rather less than one-third the 

 length of the cell, shorter than the stem of the second posterior cell, which is not 

 quite as long as the cell; posterior cross-vein shorter than the mid cross-vein, not 

 quite its own length distant from it. 



Halteres with pale stem and fuscous knob. 



Length. 4 to 5 mm. 



Habitat. Itacoatiara, Lower Amazon (Austen) ; Rio de Janeiro (Lutz). 



Time of capture. February (Amazon). 



Observations. Specimens of this species have been received from Dr. Lutz and 

 were named by him Janthinosoma discrucians, Wlk. I have compared them with the 

 type in the British Museum and find they do not agree. It is clearly a new species, 

 which can easily be told from Walker's C^llex discrucians by the last two hind tarsi 

 and the apex of the antepenultimate one being white and by its larger size. In C. 

 discrucians " the base of the fourth joint is adorned with a pale yellow band," and is 

 so figured by Arribalzaga (Plate IV., fig. 6). C. discrucians is a Janthinosoma (vide 

 Appendix). 



It might also be confused with J. musica, Say, but the honey-coloured head in that 

 species and the non-ornamented thorax should at once separate them. From /, 

 posticata it can be told by the last tarsal and apex of the penultimate one only being 

 white in that species. 



Dr. Lutz writes me that " it occurs in damp woods and shady river shores. It 

 stings in the daytime. The larva is green. Common in Brazil." 



Original DESCRrPTiON op Janthinosoma discrucians Theobald, not Cuxex 

 DISCRUCIANS Walker. 



Thorax deep brown, with bronzy brown median scales, with lateral pale creamy 

 ones. Abdomen metallic purple, with apical lateral silvery white spots ; venter with 

 apical silvery white bands. Legs deep metallic violet, bases of the femora pale, last 

 two hind tarsi white. 



$. Head black, with flat spindle-shaped creamy scales in the middle; flat, violet, 

 yellow and black scales laterally and narrow brown upright forked-scales; palpi, 

 proboscis and antennae deep blackish-brown. Thorax black, with narrow curved 

 black scales in the middle of the mesonotum and flat spindle-shaped creamy ones at 

 the sides; scutellum black, with five black bristles to the mid lobe; metanotum deep 

 brown; pleurae black, with flat creamy white scales. Abdomen metallic violet, with 

 apical lateral creamy white patches to all the segments except the last, the lateral 

 patches most prominent on the apical segments; venter with apical bands of creamy 

 white scales; posterior border-bristles black. 



