122 DIPLOPODA. 
i. No subsidiary tooth or process on upper side of tibio-femoral segment 
of phallopod; the terminal processes pointed. . . « medius. 
. A distinct subsidiary tooth near the middle of the upper surface of the 
tibio-femoral segment ; the terminal processes truncated. . . . . megicanus. 
e'. Apex of tibio-femoral segment of phallopod simple and undivided ; subsidiary 
process represented by a broad excrescence. 
j. Subsidiary process nearer the base than the apex of the segment, the portion 
beyond it long and slender; femur of first leg without basal process ; 
socket of phallopods not extending laterally as far as the spiniform tubercle, 
the rim not raised ; the sternal area between the legs very wide . . . . cortaceus. 
Subsidiary process nearer the apex than the base of the segment; the area 
beyond it comparatively short; femur of first leg with conical basal 
process. ew ee ee SAUSSUFER, 
1. Spheriodesmus oniscus, sp. n. (Tab. VIII. figg. 8-8 6.) 
g. Colour (in alcohol) a uniform dark olive-green. Segments shining, but lightly punctured and coriaceous. 
First tergqal plate wider than head, with lateral angles well developed and acute but apically rounded. 
Second shorter on each side than the third. Fourth expanded laterally to a comparatively small extent, 
its antero-lateral border weakly convexly produced, its posterior border only lightly concave, and its 
antero-inferior edge lightly rounded. Fifth with its lateral portion slightly wider than that of the fourth, 
its inferior edge rounded, its posterior border very lightly concave. Sixth about as wide laterally as that 
of the fourth, although differently shaped and slightly wider than that of the seventh. The posterior 
borders of the keels from the sixth to near the hinder end of the body in the same vertical straight line 
as the posterior border of the dorsal part of the segments; the two borders forming a widely rounded 
angle on the eighteenth. Legs beset with numerous short hairs. 
In the male the first leg is a little thickened, but the femur has no excrescence or hollow inferiorly. Sterna 
of third, fourth, and fifth segments about as wide as the length of the second segment of the leg. Rim 
round socket lodging phallopods abruptly raised into a round crest on each side just in front of the coxa 
of the posterior leg of the seventh segment; the socket extending outwards to the adjoining spiniform 
tubercle. Sternal area between posterior legs of seventh segment much wider than length of second 
segment of leg. Basal segment of phallopod stout and laterally extended; distal segment projecting 
forwards parallel with that of the opposite side, abruptly curved upwards at the distal end, the termination 
slightly spatulate, with a short external process and a short recurved slender process. Near the base of 
the segment there rises a submembrauous, pointed, compressed, triangular process. 
Length 19 millim., width 7. 
Hab. Mexico, San Andres Tuxtia in Vera Cruz. 
2. Spheriodesmus robustus, sp. n. (Tab. VIII. figg. 7-7 /.) 
3. Colour olive-green. Seyments shining, nearly smooth. Form of the tergal plates much like that of the 
preceding species, but the keel of the first less produced laterally, and of the second a little wider as 
compared with the third; the fourth with its keel also a little wider, its anterior border more rounded. 
On the fifth the sulcus defining the thickened rim does not extend beyond the middle of the lower edge. 
Posterior border of the keels in the same vertical line as that of the dorsal portion of the segments ; 
those of the eighteenth forming a widely rounded angle. 
First leg of male modified, thickened, a long dentiform tubercle at the base of the femur which is hollowed 
inferiorly and widely rounded above; a smaller hair-tipped tubercle on the lower side of the two 
succeeding segments, Sternal areas of fifth and sixth a little narrower than in the preceding species. 
Margin of socket of phallopods evenly elevated posteriorly and laterally. Sternal urea between posterior 
legs of seventh segment much wider than length of second segment of leg. Phatlopods with basal 
