SPIROBOLUS. 77 
high as the pore, and on the third and fourth tergal plates they take the form of rounded tubercles. The 
dorsal and lateral areas of the posterior portion of the terga are anteriorly rugulose, posteriorly nearly 
smooth. There is no distinct longitudinal groove either in the dorsal middle line or behind the pore. 
The transverse sulcus is almost lost dorsally in the sculpturing of the terga, but lies in the transverse 
depression. Anal segment with tergal plate finely punctured ; its angular caudal portion sharply defined 
by a deep groove and much more coarsely and closely punctured ; valves nearly smooth, finely punctured, 
_ with margins compressed ; sternal plate angularly pointed. 
Number of segments 44. Total length 112 millim.; anterior width 11, median width 14, width of anal 
segment 9. 
Hab. GuateMALA, Costa Cuca, Pacific slope (0. Séoll). 
Although based upon a single female specimen, the characters of this species are 
well-marked. It appears to differ from all those hitherto described in the presence of 
the strong ridges terminating posteriorly in spines upon the lateral portion of the 
posterior area of the tergal plates. An indication of similar spine-armature is seen in 
S. fossulifer ; but in the latter the ridges are much finer, and terminate posteriorly in 
fine serration. ‘Two more features that may be mentioned are the acutely triangular 
sternal plate and the deep transverse sulcus that marks the caudal prolongation of the 
anal segment. 
3. Spirobolus stolli, sp.n. (Tab. VII. figg. 3 a-e, 4.) 
Colour piceous, or olivaceous with the posterior borders of the somites piceous, sometimes rufescent; legs and 
antennee piceous or fuscous. Body nearly cylindrical. 
Head finely punctulate above, with coarse punctuation below, 3 or 4 labral pores on each side, the vertical 
suleus marked above and below, obsolete in the middle. Antenne a little shorter than the head. First 
tergal plate with its anterior border sinuate on a level with the eye, the border defined by the groove 
straight, the posterior border of the lateral portion also nearly straight, the angle acute, rounded. The 
second tergal plate excavated below, the posterior angle rounded but rectangular, the anterior angle 
rounded and scarcely produced anteriorly. The third segment also with its postero-lateral angle convexly 
rectangular. The rest of the segments nearly smooth above, only very finely coriaceous and punctulate. 
The transverse sulcus complete or, in large examples, almost entirely obsolete dorsally ; the pore-sulcus 
almost obsolete in adults. The anal segment large; the valves with their margins not compressed, or at 
most very slightly so; the sternal plate very obtusely angled or sometimes with merely a convex 
posterior margin. 
3 smaller and slenderer ; the 7th somite a little swollen ; the cox of 3rd to the 7th legs a little produced 
posteriorly, the dilatations subequal; the second and third segments of these same legs inferiorly crested. 
Copulatory apparatus very like that of S. godmani; but the inferior processes of the anterior laminw are 
shorter, scarcely emphasised externally at the base by a notch, and the inferior angle of the posterior 
lamina is more curled and not bifurcate. 
Number of segments 41-43. Measurements of large 2 : length 110 millim. ; width 12, of first segment 10-5, 
of anal segment 9:3; height of anal segment 9°5, of median segment 10-2. Of ¢ : length about 82, 
width 9. 
Hab. Guatemata, Pachuta (0. Stoll). 
Easily distinguishable from §. godmani by the difference in colour, the form of the 
first and second tergal plates, of the copulatory apparatus, &c. 
Apparently allied to S. tzendalus of Saussure in the obsoleteness of the transverse 
sulcus, the feeble development of the lateral strie, the form of the first and anal tergal 
