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Wisconsin Academy of Sciences , Arts and Letters. 
thoracic appendages, is to be considered as truly homologous with the 
pleuropodia of embryo insects. 
It has long been known that species of Campodea bear on the first ab¬ 
dominal segment a pair of two-jointed appendages homostichous with the 
meta-thoracic legs. No such appendages appear on any of the other ab¬ 
dominal segments; a fact which would seem to indicate that they either 
still subserve some particular function or are the rudiments of once func¬ 
tional organs differentiated from a pair of probably ambulatory append¬ 
ages. As I have been unable to obtain sx^ecimens of Campodea for study, 
and can find no record in the literature to which I have access of any ob¬ 
servations made from sections of this pair of curious appendages, I cannot 
decide which of these conjectures is the more probable. Be this, however, 
as it may, Campodea is to be regarded as a form, which, so far as its append¬ 
ages are concerned, remains throughout life in a stage corresponding with 
the Orthopteran or Coleopteran embryo just after revolution. 
The second to seventh abdominal segments of Campodea present each a 
pair of small unsegmented styliform appendages. These contrast in size 
and shape with the pair of appendages on the basal segment. In Japyx 
the differentiated basal abdominal appendages of Campodea are replaced 
by styliform appendages, pairs of which also occur on the second to seventh 
segments. In Nicoletia and Machilis styliform appendages occur on the 
second to ninth abdominal segments. Machilis also presents similar pro¬ 
cesses on the coxal insertions of the meso-and metathoracic legs. The 
number of these style-like organs varies in different species of Lepismina. 
In Lepisma saccharina such appendages occur only on the eighth and ninth 
abdominal segments. Oudemanus [’89] has found them on the seventh to 
ninth abdominal segments of Thermophila furnorum. 
These paired styliform processes are not regarded by Haase as homo¬ 
logous with the true abdominal appendages of the Symphyla and Myrio- 
poda, but as homologous with the coxal spurs of the lower Tracheata. 
He consequently maintains that the real appendages to which they be¬ 
longed have disappeared on all the abdominal segments of Machilis and 
its allies and on all except the first abdominal segment of Campodea. 
Haase supports this view with the following facts. In their structure the 
styliform appendages resemble very closely the spines and spurs so com¬ 
mon on the body and legs of the Tracheata. They are unsegmented and 
unlike true appendages contain no muscular core. They correspond in 
structure, and in their method of insertion with the coxal spurs of Myrio- 
pods, Scolopendrella , Thysanura and certain Blattce [notably South Amer¬ 
ican Blaberidae]. Haase, who seems to have given very careful attention 
to this subject, is very probably correct in his conclusions in regard to 
these styliform appendages, or “ pseudozampe,” as they are called by 
Grassi; still the proof cannot be regarded as complete till their early de¬ 
velopment has been studied. 
Though the appendages under consideration contain no muscular tissue 
