PHYLACTOPHALLUS.—CYCLORHABDUS. 167 
anal sternal plate subtriangular, but not sharply pointed. Sterna moderately broad. Lateral surface 
coriaceous. A crest above the legs of the posterior pair on all the segments in the anterior half of the 
body. Legs moderately long; the anterior shorter and thicker than the posterior; the terminal segment 
of the legs of segments 1 to 8 very short, only about half as long as the penultimate segment, which is 
prolonged inferiorly beneath its proximal end as an arthrodial pad; terminal segment a little longer 
than the penultimate in the segments from the 9th to the end; the second segment of all the legs 
thickened and conically elevated above, the thickening gradually becoming smaller towards the end of 
the posterior half; third segment always rather short, thickened and convex above on the anterior legs, 
incrassate on the posterior legs; fourth segment shorter than fifth, the two together longer than the 
third or sixth segments. Seminal processes of cox of second leg short and rounded ; two small tuber- 
culiform excrescences on the anterior border of the sternum of the third segment. Socket of phallopods 
large and wide, its border elevated behind, and widely separating the coxse of the posterior legs of the 
seventh segment. Phallopods with coxal segments large and coarsely hairy in front; distal segment 
with femoral piece also coarsely hairy, but the hairs shorter; this segment directed forwards, stout and 
short, with its terminal portion bent upwards at a right angle, and inclining a little outwards, and near 
the middle of its outer side there arises a large subquadrate Jamina projecting outwards and downwards ; 
the tip of the organ is hcoked backwards and bluntly emarginate towards a short subcylindrical process 
(? the seminal stile) which arises from the upper side of the segment. 
Length, ¢, 23 millim., width about 2. 
Hab. Costa Rica, Irazu (fogers). 
It is possible that the genus Rhachidomorpha may have to come into this section of 
the Polydesmoidea, and not into the Rhachidesmine, where it is placed in this 
enumeration. ‘The doubts that envelop the systematic position cf the genus have 
arisen from our ignorance of the male-characters of the Mexican specimens described 
by Saussure as Rhachidesmus tarasea, the typical species of the genus, and from the fact 
that Attems has described as 2. tarasca a specimen from Espirito Santo in Brazil, 
which unquestionably belongs to the section Leptodesmine. In this example the 
phallopod has a distinct calcar and terminates in three branches—a superior arising 
from the femoral portion, and two, one above the other, from the terminal or tibial 
portion, the upper of these bearing the seminal duct, and the lower or aboral being 
an auxiliary branch. But whether or not the true &. tarasca possesses this type of 
phallopod, it differs from all the known Central-American species of Chelodesmine in 
its strongly elevated subspiniform keels. 
For further particulars concerning this species, see below, under the heading 
Rhachidomorpha, p. 174. 
CYCLORHABDUS. 
Cyclorhabdus, Brélemann, Ann. Soc. Ent. France, Ixvii. p. 279 (1898) ; Mém. Soc. Zool. France, 
xiii. p. 98 (1900). 
Allied to Dirhabdophallus, but differing in that the distal segment of the phallopod consists in the main of 
a single long, curled, and more or less twisted sclerite, without or with only very short accessory 
branches; in having the terminal segment of the legs short and supported proximally beneath by a 
forwardly directed process from the penultimate segment. 
Type, C. annulus, Brol. 
Distribution. Venezuela and Guatemala. 
