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cases in which the trochantin appears to intervene between the epi- 
sternum and coxa, the sclerite in question is not the true trochantin, 
but the trochantin fused with the lower portion of the 
pleuron. 
The epimeron in such insects as Mantispa is clearly divided into 
an upper and lower region (fig. 1, pip and h). In a previous publi- 
cation (Crampton, 1908) I termed these subdivisions of the epimeron, 
the hyper- and hypoepimeron; but since these terms were criticized as 
being confusingly similar, I later changed them (Crampton, 1909) to 
ana- and kataepimeron. In the Diptera, a sclerite homologous with the 
region pip was termed the “pteropleura” by Osten-Sacken, 1884. 
Since this term has received such widespread acceptance among syste- 
matists, it is preferable to retain it for the sclerite in question. The 
designation “pleura” however, refers to both of the pleura, or flanks. 
I have therefore slightly modified the term pteropleura to ptero- 
pleurite (pleurite means a sclerite of the pieuron) and would retain 
this designation for the sclerite ptp. For the lower division of the 
epimeron hem, the term hypoepimeron may be retained. Packard, 
1882, applies the term infra-epimeron to the sclerite hem, in some cases, 
while in others (e.g. Corydalis) he applies the term infra-epimeron to 
the meron (posterior region of the coxa). The upper region of the 
epimeron, he terms the sur-epimeron. 
In certain Odonata (Libellula, for example) there occurs behind the 
metathoracic epimeron, a distinct plate (the postpleurite, or “opistho- 
pleurite”) which is apparently a posterior sclerite of the epimeron. It 
may, however, be an abdominal sclerite closely associated with the 
thoracic region. I have not observed the homologue of this sclerite in 
other orders of insects. 
The meron (fig. 1, me) is the posterior region of the coxa (cz) 
which is divided into an anterior region, the veracoxa (vc) and the 
meron just referred to. The meron is not a portion of the epimeron as 
Snodgrass, 1909b, maintains, but is a posterior portion of the coxa, 
which is but little distinguished from the remainder of the coxa in the 
Blattidae, while in the Neuroptera it becomes distinctly marked off from 
the remainder of the coxa, and in the Diptera, it becomes somewhat 
separated from the remainder of the coxa, and is more closely connected 
with the pleural region. In the lower Diptera (Tipulidae) it is clearly 
the posterior region of the coxa, but in the higher Diptera, it becomes 
fused with the lower portion of the epimeron, forming the meropleu- 
rite (i. e. me together with h, fig. 1). In the Diptera, it has been mistaken 
for the sternum, by practically everyone. 
