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Sternites. 
The term sternum includes the entire sternal region of the segment, 
and should not be applied (in the restricted sense) to any of the sternal 
subdivisions, or sternites, since such a course of procedure will in- 
variably cause confusion. In such primitive insects as Leuctra and 
Capnia (Plecoptera) there are five well defined sternites, best developed 
in the prothorax, but partially united (although separated by sutures) 
in the other segments. These sternites are the presternite és (fig. 1); 
the basisternite, bs; the furcasternite, fs (bearing the internal 
furca); the postfurcasternite, s; and the spinasternite, ss (bearing 
the internal spina, or unpaired apophysis). 
Since he thought that the four tergites described by him in some 
insects represent the tergal regions of four vestigeal segments composing 
each thoracic segment, Macleay, 1830, considers that the sternum 
should therefore be divided into four regions, for which he proposed the 
terms “praesternum, sternum (in the restricted sense) sternellum and 
poststernum”. These, he could not find in any true insect, but states 
that they are present in /ulus (a myriopod) and Squilla (a crustacean)! 
MacLeay’s hypothesis that the four tergal subdivisions described by 
him (there are in reality only two distinct tergal plates, ss/ and psl, fig. 1) 
represent four subsegments or annuli, is regarded as wholly absurd by 
every modern investigator, so that the four sternal subdivisions assumed 
by him (he never saw them, and therefore could not figure or describe 
them for insects) do not exist. Jardine, 1913, has consummated the 
reductio ad absurdum, by following MacLeay’s principle to its 
logical conclusion and dividing the pleural region also into a “prae- 
pleura, pleura, pleurella, and postpleurella”! 
MacLeay found his sternal subdivisions only in Zulus and Squilla 
(which he considered as insects), and therefore did not apply his termi- 
nology to the sternites of true insects. MacMurtrie, 1831, was the 
first to attempt to apply MacLeay’s terminology to insects, and 
designated the pro-, meso-, and metasternum as the praesternum, 
sternum, and poststernum. The term sternellum, he simply disregarded. 
The next attempt to apply these terms to the sternites of insects was 
made by Meinert, 1867, who termed the sclerite ss (fig. 1), the prae- 
sternum; while he designated the fusion product of the sclerites bs and 
fs, as the sternum; and applied the term poststernum to the sternite 
s, in Japyx. Camerano, 1882, applies the term sternum to the 
sternite bs; and the term sternellum to the sternite fs, in Sphodrus. 
Comstock, 1902, applies the term sternellum to the sternum of the 
first abdominal segment, and to the posterior one of the two cervical 
sternites cs (which are detached portions of the first sternite); and 
