84 DIPLOPODA. 
have the anal valves shaped as in C. salvini. The four seem to be distinguishable as 
follows :— 
a. First tergal plate not extending so low as the second and not 
marked with an antero-lateral groove; no apophysis on coxa 
of thirdleginmale. . . . . . 1. 1 1 ww we we) Saalvini, sp. n. 
a’, First tergal plate extending as low as the second and marked 
with a distinct antero-lateral groove. 
b. First tergal plate less strongly emarginate laterally in front and 
marked with short longitudinal grooves behind, the angle 
rounded ; (third leg of male with coxal apophysis). . . . Aeteropygus, Sauss. & Humb. 
b. First tergal plate widely excavated in front laterally, without 
any grooves behind ; the angle acute. 
c. Tergal plates smooth and shining; (third leg of male with 
coxalapophysis) . . . . 2. . 6 . we « ee ) «nietanus, Sauss. 
c. Tergal plates punctured andrugose . ... . . . . vulvanus, Karsch. 
1. Cyclothyrophorus salvini, sp.n. (Tab. VII. figg. 6 a-d.) 
Colour (in alcohol) brownish or ochraceous, the posterior border of the tergal plates fuscous ; legs and antennee 
ochraceous. 
Body long, slender, and subcylindrical. Head convex, smooth, the sulcus mesially interrupted, with 3+3 or 
4+4 labral pores. Hyes very widely separated and ill-defined. Antenne short, thick, compressed, and 
incrassate; the second and thirdsegments about equal in length. First tergal plate with the lateral 
portion acutely angled, the posterior edge convex, the anterior manifestly emarginate and without trace 
of a sulcus. The second tergal plate projecting below the level of the first, but not inferiorly produced 
and not excavated below. The rest of the segments smooth and polished or lightly striolate and punctulate ; 
the lateral sulci extending only a short distance above the legs; the transverse sulcus not extending up 
to the pore or at least never beyond it. Pores conspicuous, high above the middle of the side. Anal 
segment with tergal plate produced above into a wide, posteriorly rounded, caudal process covering the 
summit of the valves; the latter convex, with the margins not compressed, the posterior third of each 
curving abruptly inwards to meet that of the opposite side, forming a blunt termination to the body, the 
plane of the posterior portion of the valves being convex from above downwards, but flat or nearly so 
from side to side; sternal plate triangularly rounded. 
Number of segments 49-53. Length up to 37 millim., width less than 3 millim. 
Hab. Mexico, Amula in Guerrero (H. H. Smith). 
The following species, which are known to me only from the authors’ figures and 
descriptions, appear to belong to this genus :— 
2. Cyclothyrophorus nietanus. 
Julus nietanus, Sauss. Mém. Soc. Phys. Genéve, xv. p. 565, t. 5. figg. 33 a—d, o (1860). 
? Spirobolus nietanus, Sauss. et Humb. Miss. Sci. Mex., Myr. p. 89 (1872). 
Small, cylindrical, with the seventh and eighth segments dilated. Head polished, punctured below, with 
5+5 or 444 labral pores. First tergal plate with its antero-lateral border widely emarginate, its 
inferior angle very acute and extending slightly below the level of the second, which is not produced 
