STUDIES ON CARBONIFEROUS INSECTS FROM 
COMMENTRY, FRANCE: PART IV. 
THE GENUS TRIPLOSOBA" 
By F. M. Carpenter 
Harvard University 
Among the unusual insects described by Brongniart from the Com- 
mentry shales in France was a nearly complete, well-preserved speci- 
men, apparently related to the mayflies. Now known as Triplosoba 
pulchella (Brongniart), the species has usually been considered as 
representing either a distinct order (Protephemerida) or the Order 
Ephemeroptera itself. In either case, the insect has held a unique 
position as the oldest representative of the mayfly line of evolution. 
This fossil was well described by Brongniart and it has been dis- 
cussed by Handlirsch (1906), Lameere (1917), Martynov (1923), 
Tillyard (1932), and Demoulin (1956). Aside from Brongniart, 
however, only Lameere based his account on an actual study of the 
fossil itself, the others mentioned depending on published descriptions, 
figures, or photographs. * 2 Although there has been agreement on the 
general relationships of Triplosoba, much controversy has existed ovei 
the interpretation of its venation and consequently of its phylogenetic 
position within the palaeodictyopterous-ephemeropterous complex. Sev- 
eral of these authors, including Brongniart, have attempted to con- 
struct restorations of the complete insect, these also reflecting widely 
divergent views (see plate 13). 
The present paper has been written with the hope of eliminating 
some of the uncertainties and confusion about the structure of Trip- 
losoba. It is based upon my examination of the type specimen of 
pulchella in the Museum National d’Histoire Naturelle in Paris. 
Study of this fossil was made on three separate occasions. The first 
examination was in 1938, although at that time only one counterpart, 
the poorer of the two, could be found in the Museum collection. Fol- 
lowing the publication of Demoulin’s account of Triplosoba in 1956 
The preceding part of this series, on the Caloneurodea, was published in 
Psyche 68:145-153, 1961. This study has been aided by a National Science 
Foundation grant. 
2 Demoulin’s statement (1956, p. 1), that no new examination of the fossil 
had been made since Brongniart’s description was published in 1893, is cer- 
tainly an error. Lameere studied the fossil in 1914-15, the results being 
included in his 1917 summary of the Commentry insects. Demoulin, however, 
did not examine the specimen itself, but based his conclusions on photographs. 
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