8 PLATYPTILUS. 



somewhat paler than those which I have seen 

 from the Eastern States, and seem to be almost 

 undistinguishable from the European P. zetterstedtii, 

 Zeller (Isis, 1841, p. 777). Prof. Zeller (Verh. 

 z.-b. Ges. Wien, 1873, pp. 119, 120) carefully com- 

 pares the two species. He relies, amongst other 

 points, upon the extent of the brown colour upon 

 the hind legs between the two pairs of spurs, as 

 pointing to a sure specific difference ("An der 

 Hinterschienenspitze nimmt bei diesem Texaner Ex- 

 emplar die braune Farbe weniger als den halben 

 Kaum zwischen den zwei Sporenpaaren ein, bei 

 cardui f "). 



I observe that in my Californian examples the 

 brown colour occupies fully one half of the space 

 between the two pairs of spurs. The habits of the 

 two species in their larval stages are undoubtedly 

 very distinct, the European zetterstedtii feeding singly 

 in stems of Senecio nemorensis, the American cardui 

 being gregarious on heads of thistles (Cirsium Ian- 

 ceolatum). 



Platyptilus percnodactylus, sp. nov. 



(PLATE I. FlG. 7.) 



Copite, palpis et alls anticis dilute brunneis, lituris 

 apud fasuram et marginem dorsalem, et lineola 

 subapicali pallidioribus, macula triangulari cos- 



