NORTH AMERICAN LEPIDOPTERA. 109 



from the fact that 3, which is rarely stemmed with 4 and 5, is very 

 often stemmed with the resultant. It indeed makes little difference 

 whether the vein be called 4 or 5 (the two veins being joined in 

 one), so long as the writer's view is understood. For myself I prefer 

 saying vein 5 is lost, as this brings the form of expression in line 

 with what exists beyond question in other groups of the Lejjidoptera, 

 and is as fully a statement of the fact as to say vein 5 is the one that 

 is present. 



Legs. — The le.ffs are comparatively uniform. They are, however, 

 found stoiit and very slender, short and long, closely and loosely 

 scaled. There is some considerable difference in the comparative 

 lengths of femora, tibiae and tai"si. The coxaj and femora are always 

 very much flattened, and the tibiae generally slightly so ; the tibiae 

 are^arely swollen, and then only slightly. The tibial epiphysis is 

 l)resent, is well developed, and is situated near the middle of the 

 tibia. The middle tibiae are armed at the lower end with a pair of 

 spurs ; the hind tibiae have two pairs, the one pair at the lower end, 

 the other near the middle, but somewhat varying in position. The 

 tibiae are never spinulated ; the tarsi generally are, but there is a 

 very gradual variation from hairs to S2:)ines. The tarsi are always 

 ffve in number, the end one armed with two sickle-like claws with 

 pad beneath at their point of union. 



Abdomen. — The abdomen offers few peculiarities. It is ordinarily 

 .slender, cylindi'o-conical, rarely heavy and noctuiform. The seg- 

 ments are, so far as I have observed, never tufted above, nor on the 

 side, though rarely in the male there is an anal tufting. 



In a few species there is a peculiar development of spines on the 

 penultimate segments beneath; they are not very long, are generally 

 concealed by the vestiture, and have a backward curve. These, as 

 yet, I have found only in the 9 • 



There is also a much more interesting modification of the last seg- 

 ment beneath. Sometimes without any modification, it is in other 

 cases more or less chitinized, with more or less stout supports, with a 

 central carination and a development of tufts of long hairs ; some- 

 times these are modified into filiform chitinous appendages. They 

 are found in the % only." Ordinarily they are appre.ssed, and their 

 .structure lost in the surrounding vestiture, but with the abdomen 

 bleached and moderately magnified, they are mo.st beautiful and 

 interesting, as well as distinct objects. 



