463 
WILLIAMS: HABITS OF SCUTIGERELLA. 
Scutigerella armata 
Scolopendrella subnuda 
CC 
unguiculata 
CC 
silvestrii 
cc 
caldaria 
CC 
texana 
cc 
orientalis 
cc 
vulgaris 
cc 
plebeia 
cc 
neotropica 
cc 
chilensis 
cc 
simplex 
cc 
capensis 
cc 
pusilla 
cc 
angulosa 
cc 
brevipes 
cc 
crassicornis 
cc 
antennata 
cc 
pauperata 
Hansen’s paper enumerates, then, twenty-four published species 
of the Symphyla, twelve of these belonging to the genus Scutigerella 
and twelve to the genus Scolopendrella. It is his expectation that 
many more species of both genera are yet to be found. 
Anatomical .— The first author to treat of the anatomy of the Sym¬ 
phyla in any detail was Menge (’ 51 ), whose observations were rather 
complete, and considering his lack of the later methods of work, sur¬ 
prisingly accurate. He saw the dorsal blood vessel or heart, the ovary, 
the intestine, tracheae, the spinning glands ending in the cerci, and the 
movable paired “parapods” accompanying the pairs of legs. He 
reported four Malpighian tubules instead of two, the correct number, 
and made the mistake of finding a sexual opening behind and dorsal 
to the posterior opening of the intestine. Menge considered the para- 
pods as prominences to which eggs were to be fastened. 
Packard (’ 81 ), in discussing Scolopendrella, put the Symphyla 
among the Thysanura as a suborder with the Cinura and Collembola. 
This was based on certain very evident outward resemblances which 
Scolopendrella has to the thysanuran Campodea, but was at once seen 
to be an untenable grouping. The numerous large differences, such 
as the differences in the number of legs, the presence of spinning 
glands, and cerci on the posterior end of the Symphyla, and the anterior 
genital opening in the Symphyla render such a relationship impossible. 
Wood-Mason (’ 83 ) described in detail the appendages of the Sym¬ 
phyla. “Scolopendrella has very remarkable antennae; they may 
be compared each to a series of glass cups strung upon a delicate, 
hyaline and very extensible rod of uniform thickness throughout.” 
He described the ventral sacs or abdominal vesicles (on the 2d to 
10th segments inclusive) as “a pair of huge two-lipped apertures sur¬ 
rounded by a circular wall, the summit of which is defended by a circ¬ 
let of movable spines.” He also concluded from his observations that 
