154 DIPLOPODA. 
The 2nd to the 4th tergal plates also covered with tubercles, arranged in three rows, interspersed 
with granules. On the succeeding segments the number of rows of tubercles increases from four to five 
or even six, but their linear arrangement is obscured. eels rather small, sloping in the anterior part of 
the body, but becoming horizontal in the posterior part ; anterior border lightly convex, anterior angle 
convex ; lateral border of posterior segments almost straight with a shallow notch in front, of pore- 
bearing segments more convex; posterior angle nearly rectangular, very slightly produced, more 
spiniform, those of the 18th and 19th more produced than in the preceding segments, but blunt; 
posterior border very weakly serrulate. Pore-area moderately thickened, pores looking slightly upwards. 
Metazonite of 19th smooth in its anterior third, tubercular behind. Caudal process convex in front, 
flattened and depressed behind, with rounded posterior angles and lightly couvex posterior border. Anal 
sternal plate manifestly bitubercular, the edge between the tubercles concave or straight. Lateral area 
granular up to the keels. Phallopods with seminal stile, showing sigmoid curvature, somewhat strongly 
arcuate at the base; auxiliary branch terminating in two branches, an inner shorter and nearly straight 
and an outer curving gradually inwards and upwards. No tubercles on sternwm of 7th segment in ¢. 
Length, @, up to about 70 miilim., width 10. 
” 3, 29 60 ” 9 8. 
Hab. Mexico, Omilteme in Guerrero 8000 feet (7. H. Smith). 
Very like A. klugi and A. armatus in the character of its sculpturing, but 
differing from both in having the keels smaller, more depressed, and with less 
thickened edges. As in A. klugi, the lateral margins of the keels are not manifestly 
toothed. The male of A. triramus resembles the two species of the following genus, 
in which this sex has been described, in having the auxiliary branch of the phallopod 
biramous, and differs in this respect from all the other species of Amplinus. 
POLYLEPISCUS, gen. nov. 
Differs from Amplinus in having the anal sternal plate with its distal margin rounded, that is to say, the 
area between the setiferous tubercles is produced and convex, following the curvature of the sides, as in 
Euryurus; and from the latter in having the dorsal surface sculptured as in Amplinus. The known 
species also differ from those of the genus Amplinus in having the posterior angles of the keels, at least 
towards the end of the body, strongly elongate and spiniform. 
Type, P. stollr. 
Distribution. Guatemala. 
Key to the Species. 
a. Size medium; dorsal area not granular or rugulose, the polygonal areas well 
defined, shining ; pores on 19th segment completely lateral. 
6. Polygonal areas smooth, not tubercular, except obscurely so on the keels. .  stolli. 
6. Polygonal areas manifestly tubercular . . . . . . woe ew we . furcifer, 
a’. Size large; dorsal area rugulose or granular, the polygonal areas obscured by 
the granulation ; pores on 19th segment on the dorsal side of the keels. 
c. Keels of posterior half of body with anterior border basally produced, 
posterior border from 13th to 18th stmnetly shouldered at base; 19th 
granular all over; keels yellow. . . . act@on. 
. Keels of posterior half of body, e. g. of 16th, with anterior “border less 
produced ; posterior border strongly concave, not shouldered; 19th 
granular posteriorly. 2. . 2. 6 6 1 ee ee ee ew ew we het rosculptus. 
