A NOTE ON SOME AMERICAN SIMUUID/E 155 



tification a series of this species taken by him in the forests of the Central 

 Range of the island of Trinidad, in November, 1913. From compari- 

 son of these specimens with Roubaud's species, it is evident that the two 

 species, although similar, are abundantly distinct. I therefore propose 



Simulium lutzi, new name, 



for the Simulium exiguum of Lutz. Both species are very small, very 

 compact, and have a very convex scutum. Both show a general black 

 body color and have golden scales on the mesonotum, arranged in little 

 groups forming longitudinal series, but not sharply defined lines. These 

 scales in S. exiguum Roubaud axe brilliant green aind much broader 

 than in S. lutzi ; in the latter species the scales are deep golden and 

 somewhat smaller, giving a less brilliant effect than in the other species. 

 S. lutzi is further distinguished by having on the mesonotum a very broad 

 crescentic band of pearly gray, becoming brilliantly iridescent or disap- 

 pearing altogether with the changing incidence of light, and occupying 

 the base and extending forward at the sides to near the humeri ; at the 

 anterior margin there are also two large triangular iridescent white spots. 

 In S. exiguum (Roubaud) the middle legs are pale yellowish throughout, 

 while in S. lutzi they are for the most part black. The front legs of 

 Roubaud's species are also for the most part pale, the dark color begin- 

 ning at about the middle of the first tarsal joint and involving the last four 

 joints. In S. lutzi the front tibia is brilliantly white scaled on the outer 

 side, its tip black, and the front tarsi are entirely deep black. Surcouf 

 and Gonzalez Rincones place Roubaud's Simulium exiguum in the genus 

 Eusimulium ^ and Lutz's species in Simulium as restricted by them. It 

 is difficult to see how these authors eurrived at such a conclusion, since the 

 two species are intimately related and do not present the structural differ- 

 ences indicated in their generic division.^ Furthermore, Roubaud's Eusi- 

 mulium is absolutely synonymous with Simulium Latreille, and the dif- 

 ferences indicated as generic by Surcouf and Gonzalez Rincones will not 

 serve to differentiate separate groups. 



This is a suitable place to indicate the following synon3Tiiy for another 

 South Americem species : 



Simulium dinellii (Joan). 



Melusina dinellii Joan, Bol. Minist. Agric. [Buenos Aires], xiv. No. 4, pp. 363- 

 385. text figs., pis. 1, 2 (April. 1913). 



'L. c, p. 279. ^L. c. p. 277. 



