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DIPLOPODA. 
Group V. SPIROSTREPTOIDEA. 
Elongate vermiform Diplopods resembling the Iuloidea and Spiroboloidea in general form, the segments being 
numerous and variable in number, cylindrical and compact, with coalesced sterna, and each, with exception 
of the anterior five or six and the last, bearing a pair of scent-pores. Mouth-parts normal, the stipites or 
lateral plates of the gnathochilarium well developed and widely separated proximally by the promentum, 
but considerably wider proximally than in the Spiroboloidea, the promentum being correspondingly 
smaller. Segments 1 to 3 with a single pair of legs; segment 4 apodous; segment 5 with two pairs of 
legs. In the male the seminal ducts open upon a double penis behind the legs of the second pair, and the 
copulatory apparatus is retractile within the seventh segment. It consists either of distinct coleopods 
and phallopods, as in the Spiroboloidea and Iuloidea, or of a single pair of stout distally narrowed and 
biramous sclerites, the anterior ramus bearing the seminal duct. 
So far as is at present known, the Central-American representatives of this group 
are referable to two families, the Spirostreptide and Nannolenide, which may be 
distinguished as follows :— 
a. Median unpaired plate (promentum) of the gnathochilarium narrowed 
a’. Median unpaired plate (promentum) of the gnathochilarium only slightly 
distally and continued forwards between the smaller anterior paired 
plates (lingual lobes), which are triangular, being broad in front and 
varrowed and divergent behind; the anterior portion of the promentum 
separated from the posterior larger part by a distinct transverse 
membranous line (the so-called suture) ; copulatory organs of the 
male consisting on each side of a large stout basal sclerite which 
distally divides into two branches, the posterior branch tipped with tactile 
setee, the anterior bifid and partially membranous, bearing the seminal 
duct . .. . . NANNOLENID. 
narrowed distally and not continued forwards between the smaller 
anterior paired plates (lingual lobes), which are subquadrate and in 
contact almost throughout their length in the middle line ; the promentum 
undivided ; copulatory organs of the male consisting very distinctly of 
a long posterior limb, the phallopod, and of an anterior complicated 
bilaminate apparatus constituting the coleopod . . . . . « SPIROSTREPTIDE. 
Fam. SPIROSTREPTIDZ. 
Bibliographical research for the correct generic name for the Central-American 
species of Spirostreptide shows that the nomenclature of the Neotropical genera of 
this family is in a state of confusion, which has arisen partly from the assumption, 
only recently abandoned, that the presence of pores upon the fifth segment is a generic 
character, partly from the inadequacy of the descriptions and figures of supposed 
generic features published by Silvestri, and partly from the pardonable disregard of 
Silvestri’s genera by Brélemann, whose work in other respects leaves little to be 
desired. 
