SIMULIUM. 47 



Front and face black, with a light gray reflection. Antennie yellow; the 

 distal joints somewhat brownish. Mesonotum deep black; lu front, opaqne 

 with a silvery shimmer, and with sparse, curly, golden-yellow tomentum ; be- 

 hind, shining. Pleune black, whitish pruinose. Abdomen black, the basal seg- 

 ments opaque, the distal four segments somewhat shining, and with a delicate 

 whitish pruinosity. Legs reddish-yellow ; tarsi black, except that the proximal 

 half of the middle and hind metatarsi light yellow; first and third joints of 

 the front pair each witli two long hairs; second and third joints of the same 

 pair dilated, the fourth and fifth very small ; hind metatarsi elongate and stout, 

 the following two joints a little dilated, the fourth and fifth small. Wings 

 hyaline, veins yellow. 



This species must belong to the group which is repre.sented by 

 venustum Say, and several other closely allied forms, but it is not 

 possible to say just what species the author had before him at the 

 time he wrote his description. I have not seen any species from St. 

 Vincent, which is the tj^pe locality of tarscde^ and can not be certain 

 as to its status. It is, however, highly improbable that it is the 

 pulchntm which Philippi described from Chile,^ as suggested by 

 Hunter. 



GROUP D. 



Scutum striped, the stripes three or five in number (or one central 

 stripe, gn'seum), the dorso-lateral pair curved, dilated at anterior 

 ends, and generally with the dilated portion white-poUinose, the 

 central stripe generally linear. 



TABLE OF SPECIES. 



1. Scutum with pearlaceous pollinose stripes inetalliouin. p. 48. 



Scutum with black or brown stripes; if these are pollinose they are 



never metallescent or pearlaceous 2 



2. Claws witli the base prolonged thumblike . 3 



Claws with the base dilated or slightly tuberculate. or with a small 



subbasal tooth in center in addition to the tuberculate base 5 



3. Larger species, .3-4 mm.; abdomen with long hairs laterally, and the 



black marks showing as a series of black si)ots ou the sides. 



johantififni, p. (j."i. 

 Smaller species, 2-3 mm. ; abdomen with the black marks forming 

 fasciaj : 4 



4. Outer vittje on scutum much curved, basal scale of second hind tarsiil 



joint indistinct iiicridionalr. p. 40. 



Outer vittse slightly curved, basal scale distinct forbcsi, p. 0.3. 



n. Claws simple (i 



Claws with central tooth G 



(). Scutum black, thickly white-dusted, one central black striiie on disk; 



abdomen yellow, with black dorso-central spots griseum, p. ."2. 



Scutum with at least three stripes, not thickly white-dusted ; abdomen 

 never yellow 7 



>Aufzahlung del- chllenlschen Dipteren, 1805, p. 63.3. 



