152 r Jul y- 



On this character alone, the second sub-genus if, so to speak, 

 more typical, the connection between the sub-costa and radius being 

 evidently akin to the peculiar condition which these nervures assume 

 in the fore-wings. This character in the hind-wing is obscure, and 

 is not very easily made out in many specimens with the hand lens. 

 The division, however, is in certain respects natural. 



On the above distinction in the neuration, the five species 

 referred to below would fall into the sub-geuera thus : — 



Apatania Wallengreni and stiqmatella. 



Apatelia muliebr is, arctica and fimbriata. 



A. muliebris is quite different from both groups in some respects, 

 which will be alluded to hereafter. 



In giving neuration-eharacters for his species, Wallengren seems 

 to use the points which Mr. McLachlan alluded to in his descriptions, 

 namely, the condition of the fift h apical cellule in the fore-wings, and 

 the condition of the fifth apical fork in the hind-wings, with respect 

 to its connection with the sector above it. But Mr. McLachlan's 

 references were indications of a tendency, rather than an actual 

 statement of characters, and at p. xlvi, Mon. Eev. Eur. Trichoptera, 

 Supplement, he renounced any faith he ever had in the second 

 character, and I fear the value of the former must fall in proportion 

 to the increase in the number of localities from which any particular 

 species is available for examination. There is a probability that in 

 each locality a particular type of neuration is dominant, but not 

 stable. The following analysis will serve to show that the above 

 characters cannot be used with any degree of certainty. A quotation 

 from the Mon. Rev. is given first, followed by the results of the 

 examination of the specimens now before me. With regard to the 

 first character, the condition of the fifth apical cellule in the fore- 

 wings, the following terms are used : — 



" Biangulate " signifies that the two nervures arise from the anastomosis at two 



separate points. 

 " Anastomosis " signifies that the two nervures arise from the anastomosis at the 



same point. 

 " Footstalk " signifies that the cellule is connected with the anastomosis by a foot 



stalk. 



The connection of the 8th apical fork with the sector above it in 

 the hind-wings is explained by the following terms : — 



" Nervure " means that there is a distinct nervure connecting the two. 

 " Point " means that the two are connected at or by a point. 



