340 GNATS OR MOSQUITOES — CHAPTER XIII 



less tlian one third the length of its cell. Halteres witli pale stem and 

 fuscous knob. Length. — 4 to 5 mm. 



Habitat. — Itacoatiara, Lower Amazon, Rio de Janeiro, Trinidad, 

 Aqua Santa. 



Time of ca2)tiire. — February (Amazon), December (Trinidad). 



Dr. Lutz writes : "It occurs in damp woods and shady river shores. 

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



2. JANTHINOSOMA DISCRUCIANS (Walker). 



C. discrticians. Walker; " D. S. ; " p. 430; nee J. discrucians, ArribdI. 



Wings unspotted, dusky. Last two joints of the hind feet 

 and apex of next white. Thorax dark grounded, clothed with 

 scattered yellow scales. Abdomen deep brown, unhanded, but 

 with yellow lateral spots on the hinder borders of the segments. 

 Occiput, scutellum, and bases of all the femora also bright yellow. 



This is a good sized species, the wing length being about 4*4 mm. 

 With the exception of the small yellow points enumerated above, it is 

 of a lustrous, violaceous deep brown almost throughout ; but the base 

 of the .venter is also j'ellow, and the two front abdominal segments show 

 either as entirely yellowish, or with apical banding of that tint, accord- 

 ing to the position of the insect. The armature of the long veins 

 consists of truncate and of linear scales. 



Head black ; the vertex and nape clothed with short, falciform, 

 golden scales, and erect forked ones of the same colour. Scales of 

 identical fonn and colour as the former clothe the mesonotum. Palpi of 

 $ very dark and short ; those of ^ much longer than the proboscis, and 

 nearly black throughout. The fore and mid legs have a varying amoimt 

 of dark coloration at the apices of the femora, but those of the hind are 

 golden-yellow throughout ; elsewhere the legs are deep purple. Pleurae 

 and coxte marbled whitish. 



Habitat. — South America ; Argentina, San Paolo, Brazil. 



Note. — The above is a description of Walker's type, supplemented 

 by fresh specimens sent by Dr. Lutz, but Mr. Theobald points out that 

 this cannot be Arribalzaga's species, as he clearly figures it with a 

 single white band only on the hind tarsus, the last joint of which is 

 shown as black. 



3. JANTHINOSOMA MUSICA (Say) 



(Jour. Acad. Nat. Sci. Phil, vi, p. 149). 

 = C. Mexicanus, Bellardi. 



Wings unspotted, very dusky. Last two hind tarsal joints and 

 apex of next, wholly white, but tarsi otherwise uniformly dark 

 violaceous purple. Thorax, violet-black-grounded, unadorned, 

 nude but for some scattered golden scales. Abdomen deep 



