THE PHYLOGENY OE THE TEACHEiE IN ARANEJ:. 527 
few rare exceptions — thus in the Dysderidse the tracheal 
segment has no infolding and the genital duct sometimes 
opens free on the ventral surface of the pulmonary segment 
(male of Harpactes; see my paper : 09 , fig. 40). 
Leaving the four-lunged Hypochilidm, with which I am 
unacquainted, out of account, there appears in the first place 
a small group of three families (Dysderidm, Oonopidae, 
and Caponiidse) which possess some very primitive features 
in connection with their respiratory segments. As these 
segments are of peculiar interest in connection with the 
phytogeny of the tracheae, I shall give some account of their 
anatomy before proceeding to more general conclusions. 
Material and Treatment. — The material used was the 
same as that given in my previous paper (: 09 ) with the addi- 
tion of specimens of a species^ of Oonopidae fi’om the 
neighbourhood of Cape Town. 
For following the muscles, whicli are often very slender, 
suitable differential staining is very necessary, and for this 
purpose I found very old Delafield’s haematoxylin (mine was 
thirteen years old) most excellent, even for old museum 
specimens. The sections are stained on the slide for four to 
five hours, placed in acidulated alcohol for three to four 
* As this species is a new one, I append the following description : 
Calculus n. g. Cephalotliorax broadly ovate. Ocular area transverse, 
the eyes arranged as in Orchestina. Labium short and broad, as in 
Oonops. Coxa; of pedij^alps parallel, their anterior ends widely sepa- 
rated and not converging. — C. bicolor n. sj). Pale yellowish, abdomen 
with a ]>road infuscate patch behind above, and narrowly blackened on 
each side of the spinners as well. Clypeus l^arely as wide as an anterior 
lateral eye. Anterior row of eyes, seen from above, almost straight, 
the median eyes large, a trifle longer than their distance from the 
anterior margin of cephalotliorax ; anterior lateral eyes the smallest of 
the six, distant about half their own width from the median eyes ; pos- 
terior eyes forming a row which is only very slightly wider than the 
anterior row, their distance from the median eyes greater than their 
own width. Tibia and metatarsus of first leg with 0-2 spines near the 
middle below, tibia and especially the metatarsus of fourth leg more 
numerously spined. Several females from the Cape Flats, near Princess 
and Zeekoe Vleis. Length 4 mm. Allied to Tele hius, E. Sim. 
