56 
DIPLOPODA. 
concave distally, the apex slightly expanded and notched on the inner side; posterior pair of copulatory 
feet furnished with three branches—an outer, long and flagelliform ; an inner, divided into two processes 
(an external short, an internal long, lightly geniculated and bent abruptly outwards at the apex); and 
a posterior, which is elongate, nearly parallel-sided, and curves downwards and forwards beneath the 
extremities of the other two. Number of segments about 50-51. 
Length up to about 35 millim. 
Hab. Mexico, Amula in Guerrero (H. H. Smith). 
Fig 
2. 
Explanation of Figures. 
. 1. Dwarfed appendages of second segment and genital sclerites of Paratulus aztecus, 9: a, anterior plate ; 
v, proximal segment of sclerite of vulva. 1a, Inferior aspect of genital sclerites of same: a’, vertical 
and, a”, horizontal portion of anterior sclerite ; v, distal segment of sclerite of vulva. 
g. 2. Dwarfed appendages of second segment and genital sclerites of Paraiulus stylifer, 2: lettering as in 
fig. 1. 2a. Inferior horizontal portion of anterior plate of the same. 
. 3. Dwarfed appendages and genital sclerites of Paraiulus amulensis, 2: v, sclerite of vulva. 3a. Inferior 
aspect of genital sclerites of same: v, extremity of sclerite of vulva; , horizontal portion of 
posterior plate. 
2. Paraiulus aztecus, sp.n. (Tab. V. figg. 10, 10a, 8.) 
Colour like that of P. amulensis. 
Structure of segments &c. practically the same as in P. amulensis, but the pore close to, considerably less than 
its diameter away from, the transverse sulcus, which is slightly sinuous at the spot. 
In sexual characters this species differs greatly from P. amulensis. The ventrally produced area of the second 
3. 
tergite is not so thick, its posterior border being more obliquely cut away ; the ventral border of the third 
produced to almost the same extent, and embracing the genital apparatus behind; a distinct triangular 
space, revealing the genital apparatus, between the produced area of the two segments. Genital apparatus 
very distinct; it consists in front of a broad vertical plate narrowed inferiorly and longitudinally excavated ; 
where it reaches the lower surface of the body it expands right and left and posteriorly into a transverse 
plate lying backwards in a horizontal plane, with emarginate posterior border, suboval lateral borders, 
and a deep median impression. This plate forms a complete partition between the two vulva-sclerites, 
besides protecting them below and in front; the vulva-sclerites are thick, massive, and formed of two | 
segments, of which the inferior is the stouter and rounder of the two. 
Genital organs : legs of first pair thick, like those of P. amulenss; of the second pair also very much as in 
that species, but the groove for the seminal ducts on the sternal plate much more deeply emarginate, and 
the lateral expansion longer and narrower. Inner branches of anterior pair of gonopods of seventh 
segment much less expanded proximally, with the distal extremity narrow and not notched internally. 
