‘178 ; DIPLOPODA. 
1. Pararhachistes elevatus, sp.n. (Tab. XIII. figg. 7-7 d; XIV. figg. 1-1.) 
Colour (in alcohol) pale olive-grecn; legs and antenne yellower. Body slender, attenuated posteriorly. 
Keels of 1st, 2nd, 8rd, and 4th segments directed obliquely upwards and backwards almost as much as 
in Rhachidomorpha tarasca ; those of the 5th less strongly elevated ; the following keels horizontal, except 
those at the posterior end, which are slightly elevated. Anterior border of Ist tergal plate straight, lateral 
borders of keels also nearly straight and parallel, the anterior angle rectangularly rounded, the posterior 
portion of the keels produced considerably beyond the posterior border of the median portion. ‘The 2nd, 
3rd, 4th, and 5th segments wider measured across the anterior rounded angles of the keels than across 
the posterior angles; keels of 2nd and 3rd produced considerably backwards, of 4th less so, and of 5th 
still less. In all the anterior angle is more strongly convex and rounded than the posterior angle, which, 
however, is always bluntly rounded. The antero-lateral tooth becoming almost obsolete in the posterior 
half of the body ; the anterior edge convex. Keels of the median segments much smaller than those of 
the anterior, and slightly smaller than those of the 16th and 17th segments. Dorsal area smooth; an 
obsolete transverse sulcus; upper side of keels swollen. ores looking outwards. Lateral surface of 
segments smooth, only slightly wrinkled quite at the anterior end of the body. Sterna as wide behind 
as in front, except on the 15th segment. Generative orifice in Q with raised margin. 
Phallopod in $ with moderately large coxal segment and spiniform tracheal rod; 2nd segment with its 
proximal portion hairy, especially externally, where the hairs form a longish tuft; the distal portion 
smooth, stout, bent downwards at the apex; hollow below owing to the presence of a large down-bent 
laminate outgrowth, the tip truncate with an outwardly-directed slender process, and another process 
directed forwards and downwards. Fossa of phallopods transversely elliptical, wider than the sternal 
area behind it, with evenly elevated margin. Sternal area of 5th, and especially of 6th, wide, hollowed. 
Coxal segments of 1st legs with conical processes directed forwards and downwards in addition to the 
two long, crossing seminal processes. 
Length, 2, 29 millim., width 3. 
29 fof 9 25 39 be] 2-8. 
Hab. Mexico, Omilteme in Guerrero 8000 feet (//. ZZ. Smith). 
2. Pararhachistes vertebratus, sp. n. (‘Tabv. XIII. figg. 6-6 e.) 
Q. Closely resembling the preceding in size, colour, and form, but with the keels differently and much more 
normally shaped, those of the first four segments only slightly tilted and much less strongly produced 
posteriorly ; the anterior angles of the others less rounded, more rectangular; the posterior angle also 
sharper. Margin of genital orifice much less elevated. 
Length 30 millim., width about 3. 
Hab. Mexico, Amula in Guerrero 6000 feet (HZ. 7, Smith). 
ACUTANGULUS. 
Acutangulus, Attems, Denk. Akad. Wien, Ixvii. p. 409 (1898) ; Carl, Rev. Suisse Zool. xi. pp. 555, 
559 (1903). 
Body slender, shaped as in Stronyylosoma; all the keels very small, but with their posterior angle from the 
4th backwards produced into a short but sharp spiniform process. Basal segment (coxa) of phallopods 
large, without calcar ; second segment with conspicuous seminal fossa opening distally ; when at rest the 
second segment bent at right angles to the basal and projecting forwards parallel to the ventral surface. 
Sterna of 5th and 6th segments in ¢ with a process at the base of cach leg. 
Type, A. coccineus, Humb. & Sauss. 
Distribution. Mexico. 
