220 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. I25 



between the anterior and posterior arm of either side completely over 

 to the same region of the other side, with a slight concavity between 

 the two anterior arms ; numerous rather long, simple spines on either 

 side in the region between the anterior and posterior arm ; posterior 

 arms long, reaching lateral margins ; no rectal scales. 



Simulium {S.) kompi appears closest to 5". {S.) tricornis De Leon 

 but can easily be distinguished from the latter species by the form of 

 the adminiculum, the bifid condition of the apical spine of the clasper, 

 presence of isolated heavy spine on ventral surface of clasper ; shape 

 of cercus, longer dorsal necklike extension of anal lobe, presence of 

 basal dilatation of genital rod, difference in form of median extensions 

 of arms of genital fork; form and arrangement of pupal filaments, 

 shape of cocoon ; number of rows of hooks on posterior sucker of 

 larva and form of X-shaped sclerite. 



Types. — Holotype {^ dissected from pupal skin), on 3 slides, and 

 allotype ($ dissected from pupal skin), on 3 slides, in the collection 

 of the United States National Museum ; collected from the Rio Cipres, 

 Aldea Los Pa j ales, Acatenango, Department of Chimaltenango, 

 Guatemala, June 15, 1949. 



SIMULIUM (SIMULIUM) METALLICUM Bellardi 



Simulium metallicum Bellardi, Saggio di Ditterologia Messicana, vol. i, p. 14, 



1859 (original description, male). — Dyar and Shannon, Proc. U. S. Nat. 



Mus., vol. 69, art. 10, p. 41, figs. 72-yz, 1927 (female). — Fairchild, Ann. 



Ent. Soc. Amer., vol. 2^, No. 4, pp. 712-713, figs. 13, 17, 26, and 38, 1940 



(?, <S, and pupa). — Vargas, Rev. Inst. Salubr. Enferm. Trop., vol. 3, No. 3, 



pp. 234-236, figs. 3 and ID, 1942, (c? and ? genitalia). 

 Simulium avidum Hoffmann, An. Inst. Biol., Univ. Mexico, vol. 2, pp. 207-218, 



figs. 2a, 10, 13, and 17, 1931(b) (larva, pupa, and genital rod of ?). 

 Simulium {Simulium) metallicum Bellardi, Vargas, MartInez, and Diaz, Rev. 



Inst. Salubr. Enferm. Trop., vol. 7, No. 3, p. 175, fig. 143, 1946 (larva). 



Male (pi. 25, figs. 82-84) . — 2.7 mm. long. 



Head: Holoptic. Eyes reddish brown. Antenna 490 /* long, 11- 

 segmented, tapering from basal segment onward; segment 3<i+2, 

 3 = 4 + 5, 3>ii; scape and pedicel light brown, flagellum very dark 

 brown. Palpi dark brown. Clypeus very dark brown, irregularly 

 covered with long black hairs. 



Thorax : Mesonotum black ; narrow band of white pruinosity along 

 entire periphery except at anterior margin where the band is divided 

 in the middle to form two posteromedially directed arms ; infrequently 

 these arms are contiguous ; numerous short reddish-brown to black 

 hairs over entire mesonotum, long black hairs in prescutellar region. 

 Humeral angles black, with white pruinosity. Scutellum reddish 



