246 



MR. R. M'LACHLAN ON A SYSTEMATIC 



especially as regards the words " alas albse." The posterior wings 

 are much less broad than in most of the succeeding species ; and 

 in this respect it approaches the genus Ulula. 



Grenus Ulula, Bambur. 

 (Suphalasca, part., Lefebv., Hag.) 



Wings ordinarily rather broad, scarcely dilated, the margins nearly 

 parallel, a small excision at extreme base of inner margin of 

 anterior pair, not appendiculate : network open ; posterior 

 wings without a transverse branch of the lower cubitus, and 

 with the postcosta long and sinuous. 



Antennae as long as, or longer than, the wings, furnished with ver- 

 ticillate hairs at the base ; club pyriform, rather short. 



Eyes with the upper division rather larger than the lower. 



Thorax slightly villose. 



Abdomen not so long as the wings, moderately short in the <3 



obese in the $ ; without appendices. 

 Legs with the spurs of the posterior tibiae equalling, or slightly 



exceeding, the first three tarsal joints. 

 Sab. North, Central, and South America. 



This genus approaches the aberrant forms of Colobopterus on 

 the one hand, and some forms of Cordulecerus on the other. From 

 both it may be separated by the form of the hind wings. In Cor- 

 dulecerus these are more or less excised and sinuate in the 

 anal portion of the inner margin, the shape being somewhat 

 subtriangular ; in Colobopterus these wings are narrower, especi- 

 ally at the base ; in Ulula they are gently rounded at this part, 

 though varying much in breadth according to the species. 



Species. 



I have utterly failed in my attempts to separate the described 

 species, in order to diagnose them anew. Some of them. cer- 

 tainly vary immensely, even in the same locality, according to Mr. 

 Bates's observations. On the other hand, I am convinced that 

 several names have been sunk to the rank of synonyms without 

 sufficient reason. Locality doubtless causes much modification ; 

 and this is especially noticeable in the "West-Indian Islands, each 

 of which possibly possesses what it has become the fashion to call 

 a " Darwinian species " peculiar to it. 



L U. hy^lina, Latreille. (Ascal. hyalinus, Lat. Humboldt' s Recueil, 

 ii. p. 118, tab. xl. fig. 7; Hag. N. Amer. Neurop. p. 238.— A. senex. 



