82 DIPLOPODA. 
Colour of living animal blackish ; when dried or preserved in alcohol paler, with the posterior borders of the 
segments darker. 
Body robust, cylindrical, a little narrowed in front and behind. Head with several labral pores; the sulcus 
mesially interrupted. Antenne short and compressed. yes triangular, consisting of 5 horizontal rows 
of ocelli. First tergal plate with its inferior angle rounded, the anterior border concave, the posterior 
convex. The second tergal plate projecting far below the first, its inferior border very oblique, the anterior 
angle produced, a depression marking the surface of this portion of the somite. Anal segment obtuse ; 
the tergal plate obtusely angled, surpassed by the valves, which are punctured; sternal plate very 
obtusely rounded. The rest of the segments punctulate, but smooth and shining; the transverse sulcus 
very feeble, the area in front of it finely and obliquely striolate below, the corresponding area behind it 
longitudinally sulcate. 
3. Cowa of the first and second legs thick, large and swollen; coxa of third terminated by a soft spine; of 
the fourth to the seventh pairs produced into a blunt apophysis, diminishing in size posteriorly from the 
third to the seventh and not comparable to the long stylets of S. mystecus. 
Number of segments 41-46 in g, 41-44 in 9. Length 56 millim. (contracted), width 8 millim. 
Hab. Mexico, Cuernavaca, Cuautla, Hacienda of Atlihuazan near Yautepec. 
11. Spirobolus tzendalus. 
Julus tzendalus, Sauss. Mém. Soc. Phys. Genéve, xv. p. 570, t. 5. fig. 37 (1860). 
Spirobolus tzendalus, Sauss. et Humb. Miss. Sci. Mex., Myr. p. 178 (1872). 
Described as very closely allied to S. tepanecus and S. mystecus, and especially to the latter, which comes from 
the same locality; but differing in being larger, less coarsely striate, without any transverse sulcus on 
the segments, and in having the anal tergal plate rounded at the apex and not angled. 
Number of segments 45. Length 100 millim., width about 11 millim. 
Hab. Mexico, Oaxaca. 
Unfortunately the male of this species is not known. It is highly probable that 
the type was an old and large example of &. mystecus. 
12. Spirobolus eximius. 
Spirobolus eximius, Porat, Ann. Soc. Ent. Belg. xxxii. pp. 248, 249 (1888). 
Colour (dry specimen) luteous or testaceous, with the median area of the segments spotted with ashy-black ; 
the summit of the head, the middle of the first tergal plate, the apex of the last tergal plate, and the 
margins of the valves fuscous; legs and antenne luteous, the latter sometimes annulated with 
ashy-black. 
Head sparsely but deeply punctured, rugose, more coarsely above and below, median sulcus complete or inter- 
rupted ; labral pores 4 or 5 on each side; eyes composed of about 25 ocelli. First tergal plate with 
infero-lateral portion triangular, the anterior border sulcate and lightly emarginate; the posterior 
border straight or lightly emarginate. Second segment obliquely truncate infero-laterally. The rest of 
the segments sparsely punctate and coriaceous; the transverse sulcus distinct; the lateral sulci not 
extending so high as the pores and forming a serrulate margin to the sulci; a distinct. sulcus marking the 
pore and another fainter in the dorsal medial line. Anal segment short, rugose, very widely and 
obtusely angled posteriorly; valves rugose, with thickened compressed margins; sternal plate at most 
slightly angled. 
3. Coxe of third to seventh legs strongly produced and flattened. Copwlatory organ with sternal plate 
very small; anterior lamina of coleopods very large, wide, acuminate apically ; posterior lamina apically 
incised and turned backwards. 
Number of segments 44 to 48. Length of 2 95 millim.; width 9:5, of first tergal plate 8. Length of 
6 125 millim.; width 12°5, of first tergal plate 11:2. 
