STUDIES ON NORTH AMERICAN CARBONIFEROUS 
INSECTS. 
4. THE GENERA METROPATOR, EUBLEPTUS , 
HAPALOPTERA AND HADENTOMUM* 
By F. M. Carpenter 
Harvard University 
The four genera treated in this paper, belonging to three different 
orders, have only one feature in common : all have been very 
difficult to interpret and to classify. Metropator , originally placed in 
the Palaeodictyoptera by Handlirsch (1906a), has subsequently been 
regarded as protorthopterous by some investigators and as mecopterous 
by others; Eubleptus, also placed by its author in the Palaeodic- 
tyoptera, has been made the type of a new order, Eubleptidodea, by 
Laurentiaux (1953); Plapaloptera and Hadentomum, originally 
designated by Handlirsch 1906a) as types of two new orders (Hapa- 
lopteroidea and Hadentomoidea) , have subsequently been either 
assigned to these orders or placed with uncertainty in the Protorthop- 
tera. Unfortunately, all of these genera are known only by their 
type-species, which are still represented solely by the unique type- 
specimens. From my study of these fossils, I am convinced that the 
species are not nearly so peculiar as has formerly been thought and 
that to a large extent their puzzling nature is the result of Hand- 
lirsch’s unsatisfactory figures and descriptions. I believe that Metrop- 
ator was based on the hind wing of a species of the order Miomoptera, 
that Eubleptus is very close to the family Spilapteridae of the order 
Palaeodictyoptera, and that Hapaloptera and Hadentomum are near 
relatives of other genera in the order Prothorthoptera. In the follow- 
ing account I have first redescribed the fossils in the taxa to which 
I consider them to belong and then have given the reasons for my 
conclusions on their affinities. 
I am deeply indebted to Dr. G. A. Cooper of the U. S. National 
Museum for placing these type-specimens at my disposal on the several 
occasions during the past ten years when I have found it necessary 
to examine them. They have been studied under optimum conditions, 
with various types of illumination and with the use of alcohol-glycerine 
and with ammonium chloride, which has proven to be of the greatest 
*This research is aided by Grant No. GB 2038 from the National Science 
Foundation. The previous part in this series was published in Psyche, 
71 : 117-124. 
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