1963] 
Causey — Mexiterpes sabinus 
237 
Description of male holotype. Length is about 9 mm.; width is 
0.9 mm. Body is white except for black gut contents. Length of 
antennae is 1.2 mm.; ratio of length of articles 1-7 is 2:4:5.6:6:8:312. 
Segmental setae are relatively coarse, attenuated, slightly curved, and 
in slightly oblique rows on ectal one-fourth of metatergites ; their 
length is from ^ to V\ the body width; no mucus droplets are on 
setae. Shoulders are prominent, with ectocephalic margin rounded 
and outermost seta on ectocaudal angle. No pregonopodal legs are 
modified; no tarsal setae are capitate. Legpairs 10 and 11 are un- 
modified except for the usual gland opening on coxae. Somatic char- 
acters that are not mentioned are as in species of Scoterpes and Zy- 
gonopus. 
Figure 1 is an anterior view of right half of anterior gonopods 
and their sternum ; no distinct partition is in midline of coxal region, 
which juts forward at base and is coarsely setose. Figure 2 is a 
caudal view of anterior gonopods; telopodite is wide, thick, coal- 
esced to its homologue, and has 4 short branches on caudal sur- 
face; ectal branch bears 4 stout, curved setae; if there is a plumose 
branch, it is between coxa and telopodite; opening of sperm canal, 
which is probably on anterior surface of telopodite, was not observed. 
Figure 3 is an anterior view of right half of posterior gonopods; 
sternum is thin; tracheal pouches and spiracles are large; syncoxa 
is thick, lacks a partition in midline, has 10 stout setae on ventral 
margin, and has the usual gland opening at base of telopodite; terminal 
claw is minute. 
Sternum of anterior gonopods will be described when more material 
can be obtained. 
Family Trichopetalidae Verhoeff 1932 
Species of the Trichopetalidae have either 28 or 30 body segments, 
are either pigmented or depigmented, and have conspicuous segmental 
setae. Ocelli are absent in troglobitic species ; in epigean species, 
ocelli are arranged in a single series, in irregular lunate patches, or in 
triangular patches of up to 15. Male: Legpairs 10 and 1 1 have a gland 
opening on the coxae. Anterior gonopods are coalesced ; coxal region 
is large, has one or more branches on the distal margin, and is dis- 
tinctly divided from the telopodite, which is behind it and variously 
developed. Posterior gonopods consist of from 3 to 5 articles either 
Explanation of Plate 27 
Figs. 1-3. Mexiterpes sabinus, n. gen. and n. sp. 1, Anterior view of right 
anterior gonopod. 2. Posterior view of anterior gonopods. 3. Anterior view 
of right posterior gonopod. c, coxa; t, telopodite: ts. tracheal sac: s. sternum. 
