202 DIPLOPODA. 
13. Rhysodesmus notostictus, sp.n. (Tab. XV. figg. 10, 10 a.) 
3. Colour of dorsal surface, including prozonites, mostly brown, with the keels largely yellow, and generally 
more or less distinct traces of a yellow spot on the middle of the posterior area of the metazonites ; 
anterior margin of the first tergal plate and the keels yellow ; head brown, paler below; antenne pale, 
apically brownish ; legs yellow. 
Antenne shortish, width of head equal to length of segments 2+3+4-+half of 5. 
First tergal plate with anterior border nearly evenly but lightly convex. Body lightly convex. eels 
approaching the horizontal, fairly large, overlapping, bearing a few tubercles above; anterior border 
with its crest produced forwards nearer to the body than to the anterior angle; the anterior angle 
widely and obtusely rounded, lateral border lightly convex, posterior border also very lightly convex ; 
posterior angle rectangular, sometimes sharp and a little produced ; marginal thickening rather narrow 
and evenly thickened. Pores in the middle of the border, except at the posterior end of the body. 
Interzonal groove conspicuous and complete. Sterna hardly wider in front than behind. Legs with 
distal segment only a little longer than the penultimate. 
Phallopods as in figure and description given in analytical key. 
©. More convex than male and with smaller keels. 
Length, ¢, 28 millim., width 55; length of antenne 6°5 millim. 
» 2,25 5, » 5°95 » » 8D 4, 
9 2, 33 ” » 85 9 ” 6-5 ” 
Hab. Mexico, Omilteme in Guerrero 8000 feet (Z/. H. Smith). 
Three males and three females. Two of the latter, although with the full comple- 
ment of segments, are much smaller than the third. The larger females also have the 
posterior border of the keels more sinuous and the posterior angle slightly produced. 
Tam not sure that the females belong to the same species as the males (type), nor that 
they are themselves conspecific. 
14. Rhysodesmus inustus, sp.n. (Tab. XV. figg. 11, 11a.) 
2. Colour brown above, both on prozonite and metazonite, but with the keels yellow anda stripe of the 
same colour extending across the posterior half of the metazonite and sometimes invading its anterior 
portion ; first tergal plate with its anterior border pale and the brown patch subdivided behind; head 
reddish-brown, paler below; antenne darker than the legs, which are pale yellowish. 
Antenne short ; width of head almost equal to length of segments 2-6. 
First tergal plate shortish, gradually and nearly evenly narrowed laterally, or its angle wide and rounded. 
Dorsal surface finely striolate, with a few tubercles laterally. eels depressed, of moderate size ; crest of 
anterior edge with its greatest convexity close to the anterior angle, which is somewhat prominent and 
rectangularly rounded; posterior border very slightly produced towards the base, slightly sinuous, the 
posterior angles for the most part rectangular, but a little produced owing to a slight elongation of the 
marginal thickening; lateral border lightly convex ; thickening nearly parallel-sided. Pores submedian, 
except at the posterior end. Inierzonal groove nearly obsolete dorsally except for its anterior edge. 
Sterna wide in front; posterior edge emarginate. Legs with terminal segment shortish, only a little 
longer than the penultimate. 
3 (type). Smaller, narrower, flatter; keels with posterior angle more rounded; antenne longer, width of 
head equal to segments 2-5. Phallopods as in figure and description in analytical key on p. 193. 
Length, 9, 33 millim., width 8; length of antenne 5:5 millim. 
” 3, 28 ” ” 75 3 ” ” 6 ” 
Hab. Mexico, Omilteme in Guerrero §000 feet (7. H. Smith). 
