472 PROCEEDINGS: BOSTON SOCIETY NATURAL HISTORY. 
the Scutigerellas in sight these leaves should be partly decayed, an 
open network of mid-rib, veins, and veinlets. If then the microscope 
be focussed on the water around these leaves it will be found to be 
full of Protozoa (chiefly Ciliata), rotifers, and worms. 
Since the colonies live better in such an environment, as Scutigerellas 
are to be found most abundantly in similar environments in nature 
and judging from the contents of the mid-intestine already referred 
to in figure 7 (pi. 3S), one would conclude that the microscopic ani¬ 
mals just mentioned form some part and perhaps a great part of the 
food of Scutigerella. 
General Anatomical Relations. 
There are twelve pairs of legs in the adult, the first leg on each side 
having four segments while the other legs are made up of five seg¬ 
ments each. Hansen says that the true coxa is firmly fused to the 
ventral plate and that the first movable joint is the trochanter. This 
necessitates his naming the segment after the tibia a metatarsus. It 
will accord better with the nomenclature of most authors if in this 
paper the first freely movable joint be still known as the coxa. 
At the side of the coxae of the legs behind the second pair there are 
found small movable organs, the rudimentary legs. If these are added 
to the twelve pairs of walking legs they will make 22 pairs, and if with 
Schmidt we include the cerci and the special sense bristle at the hinder 
end of the body there would be 24 pairs of legs in all. 
There are fourteen large plates or scutes on the dorsal body wall of 
Scutigerella. Latzel says there may be 15 or 16 dorsal scutes, but 
this must be meant to include an incomplete scute just behind the 
head and a variation which Scolopendrella shows at the hinder end of 
the body. 
There are then not quite two pairs of legs to one dorsal plate, which 
is the relationship in other families of millepedes. Sinclair (’95, p. 71), 
shows that a dorsal scute of a millepede should represent two plates,, 
one fused behind the other. His argument is based on fossil forms. 
In Palaeocampa anthrax each dorsal plate covers but one somite 
whereas in later fossil species, though consolidation of two plates into 
one has begun, the line of fusion is plainly visible. Hansen (’ 03 ) 
states that a transverse suture is to be seen in each dorsal scute of 
Scutigerella which separates it into unequal anterior and posterior 
parts. 
