Notes on Myriapoda, 3 
the middle line to form a single presternite. In addition to 
the plates already mentioned, there is a series of varying 
number and arrangement, which forms the eupleurium. 
For purposes of comparison, Brélemann has numbered the 
rows of these plates in the following way :— 
The row which includes the stigmata-bearing plate is 
designated by the number 1; the episternal row, the row 
nearest to the sternite, is 2; 3 is the row next below 1; 4 is 
next to 2 and consequently just above the legs, 5 is the row 
between 3 and 4, ‘Then, since each row is theoretically 
composed of three sclerites, each plate is indicated by an 
index-letter: the anterior sclerite is designated by the index 
a, the middle one by 8, and the posterior one by y (fig. 2). 
Thalthybius microcephalus. Integumentary sclerites displayed. 
st 55., sternite of the fifty-fifth trunk-segment; pst., presternite ; tg, ter- 
gite; ptg, pretergite; the other lettering is explained in the text. 
This animal has a complete eupleurium, consisting of five rows with 
every element represented. J. W. Smith & 8. G. B.-B. phot.-del. 
[After Brélemann, (3) p. 313, fig. 1.] 
Brélemann (3) points out that in all Geophilomorphs 
row 1 is constant, except that in some cases the sclerites are 
independent, while in others (Oryinz) the presclerite « may 
be fused with the stigmatiferous sclerite 8. Row 2 is 
equally constant ; only a single case is known (Trematorya) 
where the presclerite is ae: Only rarely are they 
complete, more often one or other of the three rows is 
incomplete and is only represented by two sclerites or even 
only by a single one, or again one of the rows may even be 
completely wanting. 
The sternite is often pierced by a number of minute 
circular perforations, which are collectively known as the 
1* 
