1942] 
Miocene Blasticotomidce 
47 
BLASTICOTOMIDCE IN THE MIOCENE OF FLORIS- 
SANT, COLORADO (HYMENOPTERA SYMPHYTA) 
By Robert B. Benson 
British Museum, London 
Among the fossil sawflies discovered at Florissant, Colorado, 
in Miocene beds was one described by Brues (1908) as being 
a very peculiar Tenthredinid, which he placed in a new genus 
and called Paremphytus ostentatus. At the same time he con- 
fessed that he had “not been able to locate the specimen with 
any degree of satisfaction.” Rohwer (1908, p. 526) is also 
struck by the remarkable wing-venation of this insect, which 
he placed in the Tenthredinid subfamily Phyllotominae. 
Neither of these authors was familiar with the Blastico- 
tomidse which are only known now to occur in the palsearctic 
region and neither of them therefore recognized the remarkably 
similar wing-venation of the fossil Paremphytus and the living 
Blasticotoma ( cj . Brues 1908, fig. 6 and MacGillivray 1906, 
fig. 44). The placing of Paremphytus in the Blasticotomidae 
is further supported by its apparently argid-like antennae as 
in that family. 
Brues says: “Antennae stout and thick and possibly with the 
last joint long as in Arge and its allies. However, this charac- 
ter is not very plainly to be seen on the specimen. . . . The 
similarity of the antennae to those of Arge et al. is very striking, 
but it is possible that the last joint is in reality several closely 
united ones.” 
Unfortunately without the claws of the insect it is impossible 
to tell whether Paremphytus is likely to be synonymous with 
either of the two known recent genera of Blasticotomidae, 
Blasticotoma or Runaria. Living members of the family now 
represent five known species and one subspecies. B. filiceti 
Klug is known in Europe and also as a distinct subspecies in 
east Asia including Japan. The four other species are limited 
to Japan and east Asia. As these insects are not often found 
on the wing even in districts where the larvae are known to 
