16 CHILOPODA. 
Scolopendra olmeca, Humb. & Sauss. Rev. et Mag. Zool. 1869, p. 157°; Miss. Sci. Mex., Myriop. 
p. 129, t. 5. figg. 7, 7a°. 
Colour : upper surface olivaéeous, under surface ochraceous or olivaceous ; legs wholly ochraceous or distally 
olivaceous (in specimen from Cuernavaca). 
Body robust, attenuated in front and behind, wider in front than behind. 
Head large, about as wide as long, not sulcate but conspicously punctured, considerably overlapping the first 
tergite ; with a pair of shallow impressions in its posterior half. 
Antenne short, attenuate, composed of 18 segments, of which the basal 4 are naked and the rest pubescent. 
Mawillipedes punctured ; prosternal plates long, almost contiguous, almost square, with nearly straight ante- 
rior border, furnished with 4 blunt teeth, whereof the three internal are fused, and the external separate ; 
femoral tooth of normal size, not dentate. 
Tergites punctured ; the first with a deep anterior transverse sulcus; the second to the twentieth bisulcate ; 
seventeenth to the twenty-first with raised margins. 
Sternites smooth, from the second to the twentieth bisulcate. 
Anal somite: tergite wider than long, not sulcate; plewre closely porous throughout, a single spine on its 
posterior margin, the process moderately long, smooth, armed apically and subapically with 4 spines ; 
sternite with lightly convex and converging lateral margins, and straight posterior margin ; legs moderately 
long, femur armed with about 15 or 17 spines, arranged in longitudinal series approximately as follows— 
2 on the upper-inner edge, 3 on the inner surface, 4 or 6 on the under-inner edge, and 3 and 3 on the 
under-outer edge; the middle of the under surface without spines, the process stout, of moderate length 
and tipped with two spines ; tarsus unspined, claw spurred. 
Legs: the twentieth pair with unspined tarsus, the rest with spined tarsus ; claws spurred. 
Length to 58 millim. 
Hab. Mexico !5 (Geddes, in Mus. Brit.), Puebla (Saussure ®, Botteri+), Cuernavaca 
in Morelos 5200 feet (Saussure °, H. H. Smith). 
According to Humbert and de Saussure this species frequents the plateau of Mexico, 
occurring at Cuernavaca and Puebla. S. pomacea may be recognized from the other 
indigenous Central-American species by its shorter antenne. These appendages are 
composed of only 17 or 18 segments, whereas in the others there are always more 
than 20. 
The above description is taken from a specimen in the British Museum obtained by 
Mr. Geddes, which has unfortunately but one anal leg; I am consequently unable to test 
the constancy of the spine-armature of the femur of this appendage. ‘The spines in 
Koch’s specimen seem to be fewer in number, since he indicates them as only 12, 
arranged as eras above downwards 2, 3, 3, 2, 2. In the above-described 
example they are 2, 8, 3, 3, 38, being two in excess; but I do not think this is sufficient 
to distinguish the specimens specifically. ‘There is, however, one other objection that 
may be alleged against my opinion that S. pomacea and S. chichimeca are identical. 
This is Koch’s statement that the neck-plate in his specimen is without impressions. 
But I venture to think that he is here referring to the absence of punctures or of the 
two longitudinal grooves which characterize the rest of the terga, and not to the 
absence of the deep anterior transverse sulcus. ‘This sulcus he probably never saw, 
owing to the retraction of the head-plate, which his figure indicates. 
The determination of S. olmeca as the same species is based upon the absence of 
