48 
Psyche 
[Sept -Dec. 
occur, living representatives of the family may yet be found 
in North America. The only described larva, that of B« filiceti 
Klug (Meijere 1911, p. 86, pi. v, figs. 1-12), is without abdomi- 
nal legs and bores in a fern-stem, producing a peculiar irregular 
ball of froth about the size of a walnut on the side of the 
stem. The presence of the insect in a district is usually most 
easily detected by these balls of froth. 
The representation of this family among the Florissant fos- 
sils is specially interesting because of the extreme rarity of the 
adults of the living species and suggests that they may have 
been more common as well as more widely distributed in Mio- 
cene times. 
References 
Brues, C. T. 1908. New Phytophagous Hymenoptera from the Tertiary of 
Florissant, Colorado. Bull. Mus. Comp. Zool. Harvard , 51:257-276, figs. 
1 - 10 . 
MacGillivray, A. D. 1906. A study of the wings of the Tenthredinoidea, a 
superfamily of Hymenoptera. Proc. U. S. Nat. Mus., 29:569-654, figs. 1-97. 
Meijere, J. C. H. de. 1911. Ueber in Farnen parasitierende Hymenopteren- und 
Dipteren-Larven. Tijdschr. Ent., Amsterdam, 54:80-187, pis. 5-7 (figs. 
1-40). 
Rohwer, S. A. 1908. On the Tenthredinoidea of the Florissant shales. Bull. 
American Mus. Nat. Hist., 24:521-530, figs. 1 a-e. 
