June 1899.] Dyar : On the Genus Trosia. 173 



THE MEGALOPYGID GENUS TROSIA, WITH DE- 

 SCRIPTION OF A NEW SPECIES. 



Bv Harrison G. Dyar. 



Genus Trosia Hiibner. 



1822 — Trosia HuBNER, Verz. bek. Schmett. 196. 

 i85$-+-Saat/ios Walker, Cat. Brit. Mus. Ill, 752. 

 1856 — Edebessa Walker, Cat. Brit. Mus. VII, 1755. 

 1874 — Isoc/iroma Felder, Reise Novara, Lep. IV, pi. 83. 



Kirby calls this genus Sciathos in the catalogue, omitting Hiibner's 

 term. Druceand others also neglect Trosia, perhaps from a prejudice 

 against the Verzeichniss names. In the following, species succeeded 

 by a dash are unknown to me, except by description and are referred 

 to this genus on the authority of the authors quoted. 



Synopsis of Species. 



Thorax and abdomen discolorous, thorax in part white, abdomen bright red. 

 Thorax without black marks. 



Costa broadly red ; wings in part pure white, at least in a stripe next the red 



margin I. tricolora Fab. 



Costa very narrowly red ; wings without any pure white. 



2. Obsolescens Dyar 



Thorax with a black band in front and on each side 3. purens Walk. 



Thorax and abdomen concolorous, abdomen not bright red. 



Costal margin red ; a transverse row of black dots 4. diamas Cram. 



Fore wings without marks, uniformly ochraceous 5. ribbei Druce. 



i. T. tricolora Fab. 



1787 — Bombyx tricolora FABRICIUS, Mant. Ins. II, 114. 



1790 — Bombyx punctigera STOLL, Pap. Exot. suppl. pi. 34, fig. I (nee Linn.). 



1822 — Trosia tricolora Hubner, Verz. bek. Schmett. 196. 



1855 — Sciathos punctiger Walker, Cat. Brit. Mus. 752. 



1856 — Sciathos punctiger Walker, Cat. Brit. Mus. VII, 17 11. 



1874 — Isochroma fallax Felder, Reise Novara, pi. 83, figs. 18, 19. 



1887 — Sciathos punctigera Druce, Biol Cent. -Am. Lep. I, 212. 



1892 — Sciathos punctigera Kirby, Cat. Lep. Het. I, 540. 



Kirby makes this the punctigera of Linnaeus (Syst. Nat., 509, no. 

 67), but the description does not coincide in the least with this 

 species, either in structure, color or habitat. 



2. T. obsolescens, sp. nov. 



Head white in front, red on the vertex behind the antennseand shading to red below 



