144 COLOMBIAN DERMAPTERA AND ORTHOPTERA 



Size very small for the genus, slightly less than that of A. dicranum Redten- 

 bacher, smallest of the previously known species; form moderately slender for 

 the genus. Antennae with proximal joint flattened, rectangulate, slightly 

 longer than wide, unarmed; succeeding joints elongate, straight and not en- 

 larged distad." Head with occiput armed with two transverse arcuate rows 

 of slender elongate spines, four in each row, of which the median-cephalic pair 

 are slightly the largest, before these is a sub-approximate pair of decidedly 

 smaller spines, and between these and the antennal sockets a more widely 

 separated pair of larger slender spines. Pronotum rectangulate, appreciably 

 longer than broad, armed mesad with an approximate pair of very elongate 

 slender spines, behind these showing a rather broad transverse concavity, 

 with a pair of minute approximate spinulae mesad at the cephalic margin and 

 a heavier, longer, more widely separated pair of small spines mesad toward the 

 caudal margin, each angle of the pronotum is also armed with a small slender 

 spine directed laterad. Mesonotum narrowing evenly cephalad in cephalic 

 two-thirds, narrowing slightly in caudal third, armed with a widely separated 

 pair of elongate slender spines near the cephalic margin, and with an approxi- 

 mate pair of spines mesad at end of cephalic third, which are enlarged and 

 supplied with a few spinulae at their attingent bases, armed with a transverse 

 series of four elongate, heavy, composite spines at end of caudal third, the me- 

 dian pair of which are fused in proximal portion, the lateral spines of this series 

 the longest on the insect, lateral margins supplied with elongate spinulae and a 

 transverse series of four minute spinulae near the caudal margin. Metanotum 

 with a similar, but much smaller, transverse series of four elongate, heavy, 

 composite spines mesad, and with a lateral projection on each side above the 

 coxa armed with a similar spine. Median and first dorsal abdominal segments 

 showing rudiments of four spinulae mesad at their caudal margins, and with 

 feeble smooth carinulae running from these laterad to near the latero-cephalic 

 angles of these segments, such are found caudad as far as the seventh segment ; 

 second dorsal abdominal segment with four spines mesad, of which the cephalic 

 pair are well developed and composite, these are found on each segment in 

 decreasing size to the seventh where they are subobsolete. First to seventh dor- 

 sal abdominal segments with latero-caudal angles produced in small, irregularly 

 rounded projections. Distal portion of abdomen moderately enlarged, cris- 

 tate,'^ produced, terminating in two narrow vertical lobes, which internally are 

 heavily denticulate. Cerci flattened, short, incurved. Subgenital plate short, 

 truncate distad. Femora each with an acute, dorsal genicular projection and 

 with all margins supplied with triangular plates, which are sharp at their apices, 

 these largest meso-distad. Tibiae supplied with smaller triangular plates with 

 apices sharply rounded. Tarsal joints slender and rather elongate, caudal 

 metatarsus nearly as long as combined length of succeeding joints. 



'^ In both paratypes the suc('eeding ten joints are elongate and slender, the 

 remaining eleven or twelve joints much shorter, decreasing gradually in length 

 from first of these, the thirteenth half as long as the twelfth. 



'^ Slightly more fironounced and showing three serrations in the paratypes. 



