1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 187 



sory cell of the primaries, as well as in minor features of venation, wiug 

 form, etc. 



These two genera — Gydosia and Gerathosia — furnish a very interest- 

 ing and instructive part of our Arctiid fauna, combining as they do the 

 habitus of the Lithosiidce and some of their peculiarities of venation, 

 with the presence of ocelli, leaving the latter as the sole distinctive 

 feature separating the Arctiidw from the Lithosiidw. With the Zygae- 

 nidw, Cydosia is analogous only in color, the affinities are all Lithosian, 

 and Mr. Grote and his followers have allowed themselves to be blinded 

 by this superficial character, which did not even deceive Hiibner into 

 overlooking the absolute agreement in all essential details with Lithosia- 



As Cydosia and Cerathosia form a distinct group in the Arctiidce, to 

 which the term Cydosiince may continue to be applied, I will give in 

 detail the characters of the genera and species, premising that the sub- 

 family is distinguished by the narrow primaries, ample secondaries, and 

 the conic protuberance of the clypeus. 



Genus Cydosia Westw. Dune. Nat. Libr. 37, 193. 



Head distinct, not prominent, the clypeal protuberance roughened in 

 front, not depressed centrally. Palpi minute, not exceeding front, 

 slender. Tongue strong, moderate in length. Anteume simple in both 

 sexes. Thoracic vestiture scaly, closely appressed. The legs are stout, 

 tibia? gradually becoming longer posteriorly ; the median tibia with one 

 pair, posterior with two pairs of spurs. Abdomen cylindric, stout. The 

 genitalia will prove interesting, but they are small and not easily made 

 out, and I have no material for dissection. 



In detail the venation is as follows: Primaries, 12- veined ; vein 1 

 free, not furcate at base; vein 2 from median, about three-fifths from 

 base; veins 3, 4, and 5 nearly equidistant from 

 the end of the median vein ; vein 6 from the ex- 

 treme end of the subcostal ; veins 7, 8, and 9 on 

 one stalk, 9 nearest to base, 7 and 8 forking very 

 close to the apex ; vein 10 from subcostal, as far 

 from 7 as the latter is from 6; vein 11 from sub- 

 costal, three-fourths from base, free tocosta; vein 

 12, the costal vein, from base, free, parallel to 

 costa, which it joins three-fifths from base. 



Secondaries lacking vein 5. Two internal veins 

 as usual; vein 2 from the median, half way to 

 its furcation forming veins 3 and 4 ; G and 7 



formed by the furcation of the subcostal ; vein 8 from the subcostal about 

 one-third from base. 



Mr. Edwards assures me that the Texan form is perfectly identical 

 with the West Indian form which Cramer named nobilitella, and this 

 name must therefore be restored and imitella Stretch cited as a syn- 

 onym. 



Venation of Cvdosia. 



