52 
FLATYRRHACID^. 
rounded ; sterna with a prominent conic process at the base of each leg ; dorsal 
surface finel}’- and evenly granular, the granules not prominent ; tubercles dis- 
•tinct but not conspicuous; areas indistinct ; lateral margin of carinae with sev- 
eral long, bead-like, smooth granules, which are somewhat pointed on posterior 
segments ; anterior and posterior margins of carinae finely and sharply den- 
tate ; Genus Cyphorrhacus, 7tov., C. andhtus, sp. n., Ecuador, U. S. Na- 
tional Museum. 
Dorsum moderately convex or flat, the carinae more or less horizontal ^ 
carinae of segment iq broad and rounded at the posterior corners; last seg- 
ment usually broadly truncate ; geneia which may not be clearly eliminated 
by the above characters have either the sternal spines small or obsolete, the 
dorsum coarsely granular or finely so, and with the tubercles obsolete, the 
areas distinct or entirely absent, the lateral margins subentire, with coarse 
granules, or with large pointed teeth, the anterior margins of the carinae 
smooth or beaded with rounded granules, or some combination of these 
characters. ............. 
Carinae of moderate width, with a prominent, square shoulder at base in 
front; dorsum densely beset with distinct, prominent, rounded granules and 
divided into three transverse rows of polygonal areas, each of which has a dis- 
tinct, though not conspicuous tubercle in the middle ; tubercles of the poste- 
rior row much more conspicuous than the others ; first segment with an ante- 
rior row of large tubercles, behind which is a distinct transverse depression 
vertex densely and finely granular, prominent and subcri.state on each side of 
the sulcus ; pores removed from the margin by five or six times the diameter 
of the small ring ; clypeus smooth and shining below : Genus Psammodesmus 
nov., type Ps. cos, sp. n., Colombia, Philadelphia Academy. 
Carinae broad and wing-like, with the shoulder slight or wanting ; dorsum 
with very fine, sparse or flattened granules ; or if the granules are strong 
there is no trace of areas, and the carinm not very wide, the first segment has 
no large anterior row of granules, the vertex is rounded and with rather scat- 
tering coarse granules, or the pores are close to the margin or removed from 
it by only two or three times the width of the large and prominent rings. . 
Pores situated in the posterior half of the carina, just above the lateral edge, 
which is entire or subgranular ; dorsal surface divided into large areas sug- 
gesting those of Polydesmus; copulatory legs small, rather slender, the apical 
processes subequal in length, strongly divaricate: Genus Nanorrhacus nov,, 
type N. lucioe (Poc.), Santa Lucia, West Indies, British Museum. 
Pore near the middle of the carina, remote from the margin by at least two 
or three times the diameter of the ring; lateral edge nearly always distinctly 
granulate or dentate, with the posterior corner acute and distinctly produced , 
areas either wanting or numerous ; copulatory legs with the ultimate divisions 
unequal, approximate or connivent. ........ 
Dorsum densely beset with equal, prominent, rounded granules; the tuber- 
cles similar, but larger, the three rows about equally distinct ; areas entirely 
wanting; lateral margins with large, rounded, bead-like granules; first seg- 
ment with no specially enlarged granules in front ; copulatory legs divided 
immediately above the hairy portion into two slender subapproximate pro- 
cesses, the anterior of which is longer ; both processes are strongly curved 
cephalad, and the larger is bent nearly into a circle : Genus Rhyphodesmus, 
nov., type Rh. terininalis, sp. n., Museum. 
