LEPIDOPTERA. 167 



night. He appears to have accepted the term in 

 its last meaning, or at all events as having refer- 

 ence to creatures more remarkable by night than 

 day, which might very fairly be applied to that 

 section of the Moth family generally considered 

 to fly during the night, and to remain dormant 

 or concealed during the day. 



Latreille accepted the principle of division by 

 the time of flight which had been thus put forward 

 by Linnaeus, but abandoned the fanciful terms of 

 the great Swedish naturalist, and adopted more 

 descriptive ones ; calling the first division Diurna, 

 or day-flyers, from the Latin diurmis, meaning that 

 which is done in the daytime, or belonging to the 

 day; the second, the Crepuscularia, ovtwihght-Qjers, 

 from the Latin crepusculum, the twilight ; and the 

 third, the Nocturna, or night-flyers, from the Latin 

 nocturmis, appertaining to the night. 



It has since been found, however, that the time 

 of flight is not an infallible method of distinction, 

 except in the first class, several species, both of the 

 second and third classes, having been found to fly 

 by day as well as night. The principle recently 

 proposed by Dr. Boisduval to separate the order 

 Lepidoptera only into two great classes, founded 

 on distinctions of the antenna?, has therefore been 



