BRISTLE-TAILS AND SPRING-TAILS. 95 
tom of the group. . It has the long, linear, scaleless body of Cam- 
podea, in the family below, but the head and its appendages are 
like Lepisma, the maxillary palpi being five-jointed, and the labial 
palpi four-jointed. The eyes are simple, arranged in a row of seven 
on each side of the head. The abdomen ends in three long and 
many-jointed stylets, and there are the usual ‘“ false branchial feet” 
along each side of the abdomen. There are two European species 
which occur in green houses. No species have yet been found in 
America. 
The next family of Thysanura is the Campodeæ, comprising the 
two genera, Campodea, and Japyx. These insects are much 
smaller than the Lepismide, and in some respects are interme- 
diate between that family and the Poduridz (including the Smyn- 
thuride). 
In this family the body is long and slender, and the segments 
much alike in size. There is a pair of spiracles on each thoracic 
ring. The mandibles are long and slender, ending in three or 
four teeth, and, with the other appendages of the mouth, are con- 
cealed within the head, “ only the tips of the palpi (and of the 
maxillee when these are opened) projecting a very little beyond 
‘the rounded entire margin of the epistoma,” according to Haliday. 
_ The maxille are comb-shaped, due to the four slender, minutely 
ciliated spines placed within the outer tooth. The labium in 
Japyx is four-lobed and bears a small two-jointed palpus. The 
legs are five-jointed, the tarsi consisting of a single joint, ending 
in two large claws. The abdomen consists of ten segments, and 
in Campodea along each side is a series of minute, two-jointed ap- 
pendages such as have been described in Machilis. These are 
wanting in Japyx. None of the species in this family have the 
body covered with scales. 
The more complicated genus of the two is Japyx (Fig. 24, Japyx 
solifugus Hal. ; a, the mouth from beneath, with the maxillæ open ; 
b, maxilla; d, mandible ; c, outline of front of head seen from be- 
neath, with the labial palpi in position), which, as remarked by the 
late Mr. Haliday (who has published an elaborate essay on this 
. genus in the Linnzean Transactions, vol. 24, 1864), resembles For- 
ficula in the large forceps attached to its tail. 
Campodea (C. staphylinus Westw., Fig. 25, enlarged ; a, mandi- 
ble; b, maxilla), otherwise closely related, has more rudimentary 
mouth-parts, and the abdomen ends in two many-jointed bristles. 
