1967] 
Carpenter - — Cretaceous Insects 
273 
In the Alloraphidiidae and Mesoraphidiidae MA and MP of the 
hind wing arise independently from the stem R + M ; in the Inocel- 
liidae and Raphidiidae MA and MP arise from the common stem 
M, after its separation from R. On the other hand, in none of the 
previously known extinct families, including Mesoraphidiidae, does 
MA in the fore wing arise far distad of the fork of MP, as it does 
in the Alloraphidiidae. This feature does occur in the Inocelliidae 
and Raphidiidae, but it is obviously of an independent origin. 
The Alloraphidiidae provide additional evidence for the conclusion 
that in the Mesozoic era the snake-flies were a far more diverse 
group than now, representing still another line of evolution within 
the order. In addition to the family Mesoraphidiidae, which is known 
from the Jurassic of Turkestan, the family Baissopteridae is known 
from the Upper Jurassic of Trans Baikal; this includes species which 
had more venational branches and more cross veins than the Meso- 
raphidiidae or the existing families (Martynova, 1961). It is inter- 
esting to note, however, that MA arose in the hind wing of the 
Baissopteridae just as it does in the Mesoraphidiidae and the Al- 
loraphidiidae (see plate 35). The excellent preservation of the 
Jurassic snake-flies from the USSR shows clearly that, apart from 
the wings, their body structure was remarkably like that of the 
existing families, even to the prothorax and ovipositor (Martynov, 
1925b, Martynova, 1962). The Oligocene snake-flies ( Baltic amber ; 
Florissant and Creede Shales, Colorado) belong not only to Recent 
families but to existing genera, though these genera, in the Tertiary 
show quite different distributional patterns from those which they 
possess now (Carpenter, 1936, 1956). 
EXPLANATION OF PLATE 35 
Fig. A. Mesoraphidia pterostig malis Martynova, fore wing; Upper Juras- 
sic, USSR (Kazakstan). Length of wing, 13 mm. After Marty- 
nova, 1947. 
Fig. B. Mesorophidia pterostig mails Martynova, hind wing; Upper Juras- 
sic, USSR (Kazakstan). Length of wing, 12 mm. After Marty- 
nova, 1947. 
Fir. C Baissoptera martinsoni Martynova, fore wing; Upper Jurassic, 
USSR (Buryatskaya A.S.S.R.). Length of wing, 13 mm. After 
Martynova, 1961. 
Fig. D. Baissoptera koloznitsynae Martynova, hind wing; Upper Juras- 
sic, USSR (Buryatskaya A.S.S.R.). Length of wing 12.5 mm. After 
Martynova, 1961. 
