26 CHARLES P. ALEXANDER 



flection of ^^4+5', cell ist J/j closed; basal deflection of Cui at or very close to 

 the fork of J/. 



Abdomen dark brown, the valves of the ovipositor redd.sh horncolor. 

 Ovipositor with the tergal valves straight, rather long and slender; sternal 

 valves but little shorter than the tergal valves. 



Habitat. — Endemic in the Juan Fernandez group. 



Holotype, $, Masatierra, December. — Paratopotypes, 2 $'s, January and 

 July. — Paratypes, 3 $'s, Masafuera, February, March. 



Type in the Riksmuseum in Stockholm. 



This dark-winged Dicraiiomyia with its dark reddish praescutum does not 

 agree with any of the numerous species of the genus described from the Chilian 

 mainland. It is dedicated to the memory of Alexander Selkirk — » Ro- 

 binson Crusoe* — , who spent the years between 1704 and 1709 on the island 

 of Masatierra. 



Subfamily Tipulinae 

 Tribe Tipulini 



Genus Tipula Linnaeus 

 Tipula backstroiiii, sp. n. 



Antennae bicolorous; mesonotal praescutum reddish brown with two 

 narrow, dull yellow stripes, one on either side of the capillary median brown 

 vitta; halteres dark brown, the base of the stem yellowish; femora with a 

 narrow dark brown ring before the tip; wings uniformly brownish gray, stigma 

 dark brown. 



Female. — Length about 22 mm.; wing, 18 mm. 



Frontal prolongation of the head brownish yellow; nasns distinct; palpi 

 dark brown. Antennae with the four basal segments light yellow, the inter- 

 mediate flagellar segments indistinctly bicolorous, the apical flagellar segments 

 more uniformly brown; verticils moderately elongated. Head grayish brown; 

 a capillary dark brown median line extends the whole length of the vertex 

 onto the vertical tubercle. 



Mesonotal praescutum reddish brown with faint dull yellow stripes, the 

 most distinct being one on either side of a capillary dark brown median vitta; 

 the brown lateral stripes are indistinct, separated from the median stripe by a 

 very faint yellowish border; scutum brown, sparsely gray pruinose; scutellum 

 and postnotum pale brown, the latter sparsely gray pruinose. Pleura yellowish, 

 with a very sparse white bloom. Halteres dark brown, the base of the stem 

 abruptly yellowish. Legs with the coxae yellowish, with a sparse white bloom; 

 trochanters dull yellow; femora dull yellow with a rather narrow, dark brown, 

 annulus immediately before the tip: tibiae yellowish brown, the tips narrowly 

 and indistinctly darkened; tarsi pale brown, becoming darker on the terminal 

 segments; legs long and slender, the tibiae a little longer than the metatarsi. 

 Wings with a strong brownish gray sufl"usion, the costal cell more yellowish, 



