108 DIPLOPODA. 
distinct sculpturing, except vague longitudinal striole. Transverse sulcus marked below the pore with 
semicircular strie. 
Number of segments 44. 
Length 28 millim. ; width 1:90. 
Hab. Costa Rica, Cariblanco 600 metres (Biolley 1). 
Group VI. STEMMIULOIDEA *. 
Elongate vermiform Diplopoda, with a large and variable number of segments as in the [uloidea, Spiroboloidea, 
and Spirostreptoidea, but with the body compressed and the segments not completely annuliform, the 
sternal plates being free as in the Colobognatha and the pleure separated from the terga posteriorly 
though united to them anteriorly. Mouth-parts with mandibles three-jointed ; gnathochilarium with the 
promentum short and the lingual lobes correspondingly large, almost as wide, and in some cases (that is 
to say, in the males of some species) as long as the stipites, which are themselves subparallel-sided. 
Segments without any distinct transverse sulcus, obliquely striate longitudinally, the pores situated high 
up on the sides. One or two large ocelli on each side of the head. Legs composed of eight segments. 
In the males there is a long unpaired, apparently two-jointed, penis lying behind the legs of the second pair, 
which are modified to form a pair of hook-like processes; and the two pairs of appendages of the 
seventh segment are converted into a copulatory apparatus. 
Distribution. Tropical America, Africa, and Ceylon. 
The above-quoted characters of the group have been taken from Mr. O. F. Cook’s 
paper (Amer. Nat. 1895, pp. 1111-1121). 
Fam. STEMMIULIDA. 
Characters of the group. 
The little-known and comparatively small number of species belonging to this 
family have been referred to two genera, which may be distinguished as follows: — 
a. A single ocellus on each side of the head; gnathochilarium alike in the two 
SEXES 2 we ee ee ee toe eee STEMMIULUS. 
a’. Two ocelli on each side of the head; gnathochilarium different in the two 
SEXES . Diopstvuuvs. 
So far as is known, Stemmiulus occurs only in ‘Tropical America. The type is the 
species cited below. The genus Diopsiulus was proposed by Silvestri (Boll. Mus. 
Torino, xii. no. 805, p. 3, 1897) for the three Liberian species described by Cook, 
D. bellus being the type. The Ceylonese species, 8. ceylonicus, Poc., no doubt belongs 
to Diopsiulus, as also in all probability does the species from Porto Rico described by 
Karsch as S. compressus, both these forms having two eyes on each side of the head. 
* This group was inadvertently omitted from the table given on p. 41. 
