200° | DIPLOPODA. 
their posterior border lightly convex or straight, only mesially notched on the 17th and 18th segments. 
Legs longish and slender, the terminal segment much longer than the penultimate. 
Phallopods long, their distal end, viewed from below, forming a strong sigmoid curvature turning abruptly 
inwards, then forwards and outwards, the extremity not bent upwards; the auxiliary branch rising 
rather far back and projecting more forwards and closer to the main branch than is usual. 
Length, 9, 47 millim., width 9; length of antenne 9 millim. 
” 3: 36 ” ” 73 ” ” 8 ” 
ITab. Mexico, Omilteme and Amula in Guerrero 6000-8000 feet (H. H. Smith). 
9. Rhysodesmus salvini, sp.n. (Tab. XV. figg. 5, 5a.) 
Allied to &. godmani in all general structural features, with the legs and antenne long, the keels high and 
nearly horizontal ; a marked groove between the prozonites and metazonites, but differing principally in 
the following characters :—Size much smaller; colour darker brown. The anterior borders of the eels 
are straight and not markedly produced and convex at the base; the tubercles are more in evidence upon 
the dorsal surface. Phallopods very different from those of &. godmani; short, thick, slightly incurved 
and upeurved apically, with the auxiliary process short, rising near the middle of the upper surface and 
projecting obliquely upwards, then forwards at the tip. , 
Length, ¢, 32 millim., width 6; length of antenne 6°5 millim. 
» 3, 30 ” » 99; ” ” 6 ” 
Hab. Muxtco, Omilteme in Guerrero 8000 feet (1. H. Smith). 
10. Rhysodesmus attemsi, sp.n. (Tab. XV. figg. 7-7 0.) 
Colour (in alcohol) deep brown or rich reddish-brown above, with the keels yellow and the prozonites testa- 
ceous; head brown, paler below, with the antennez yellowish-brown; legs and sternal areas uniformly 
yellowish. 
Antenne shortish, segments 2-5 in 9, and 2-4-half of 5 in d, equal to width of head. Body convex above ; 
keels following slope of the back in female, more raised in male; smooth, with a few faintly defined 
tubercles laterally. First tergal plate longer than in R. flavocinctus, the antero-lateral border oblique, the 
angle much less rounded, subacute, the marginal thickening not curved. Dorsal surface without transverse 
depression between the metazonites and prozonites; the ridge not continuous with the ridge of the anterior 
border of the keel, but, owing to its strong backward bend in front of the keel, almost in the same 
transverse line with it. Anterior margin of keels nearly straight, turned slightly forwards in female and 
more strongly so in the male where it passes into the convex anterior angle; posterior border of keels 
lightly sinuous, a little convex and produced at the base, a little concave externally, becoming gradually 
more and more produced from about the 15th to the 18th, the 17th and the 18th being subspiniform, 
and the 19th dentiform and rounded. Pores not in front of the middle of the sides, on the 5th about 
in the middle, becoming gradually nearer the point of the keel posteriorly. Caudal process truncated 
triangular; anal sternal plate with median dentiform tubercle between the setiferous tubercles, which are 
close to it. Sterna much broader in front than behind, with posterior border slightly or, at the posterior 
end, more strongly sinuous, mesially depressed; anterior area a little raised or sloping gradually away. 
Legs with spines weak in the anterior, strong in the posterior half of the body; terminal segment 
longer than in R. flavocinctus, but shorter than the sum of the two preceding segments, although almost as 
long at the posterior end of the body. 
Phallopods when viewed from below acuminate, lightly inclined inwards distally ; when viewed from the side 
the main branch is straight and upbent only quite at the tip; the auxiliary branch is short and slightly 
inclined upwards and forwards, curved at the tip. 
Length, 9, 35 millim., width 9; length of antenne 6 millim. 
” 3 ) 28 99 ” 7; 9 ” 6 ” 
Hab. Mexico, Amula and Omilteme in Guerrero 6000-8000 feet (H. H. Smith). 
