THE MYKIAPODA OF NORTH AMERICA. 177 



scuto-episcutal and sterno-episternal sutures are very distinct, as well as those between 

 the primitive sterna. I have found this species around Philadelphia, although not very 

 abundantly. They appear to affect the inner bark or liber of decaying logs, especially that 

 of the locust (Robinia pseudacaeia, L.) I have, however, occasionally observed them 

 under stones. It may possibly be GeopMlus attenuatus, but that species can never be 

 determined from Say's description. 



M. MELANONOTUS. 



M. parvus, gracilis, dilute aurantiacus; litieis duabus dorsalibus, latis, nigris, e capite ad segmentum penulti- 

 inaiii ductis; capite sparse breve piloso; antennis sparse pilosis; labio, medio valde canaliculate, utrinque nia- 

 culis tribus nigris ; mandibulis intus vix denticulatis ; lateribus nigro uiaculatis ; scuto postremo dilute auran- 

 tiaco; suturis scuto-episcutalibus indistinctis; pedibus compressis, utrinque fere 50, pari postremo gracile ; sternis 

 suturis sterno-episternalibus et sulco mediano impressis. 



Small, slender, light orange, with two broad, black, dorsal lines passing from head to penultimate segment; head 

 sparsely shortly pilose ; antennae sparsely pilose ; labium medianly strongly canaliculate, on each side, with three 

 black maculae ; mandibles within scarcely denticulate ; sides maculate with black ; last scutum light orange ; scuto- 

 episcutal sutures indistinct; feet compressed, about 50 on each side; last pair slender; sterna impressed with the 

 sterno-episternal sutures and a median sulcus. 



M. melanonotus, Wood, Journ. A. N. S., new series, 1863, vol. v, p. 41. 



The two black bands are somewhat irregular and so broad that it would, perhaps, be 

 correct to describe the dorsum as black, with a single median and two longitudinal light 

 stripes. The labium has three black dots on each side, but I suspect that these are not 

 constant. The mandibles have, on their inner edge, the rudiments of a denticule. I have 

 had great difficulty in determining the number of feet, but think that fifty pairs is very 

 near the mark. 



There is in the Museum of the Academy a single specimen, collected in Georgia by Dr. 

 John Le Conte. The length is about an inch. 



M. LIMATUS. 



M. aurantiacus?, venuste politus ; capite appendicibusque saturate rubris, segmento cephalico ordinatim punc- 

 tata, a front e ordinatim angustato, segmeuto.basali labioque lfevibus; antennis sparse longe pilosis; labio valde 

 emarginato, medio leviter canaliculate; mandibulis magnis, pilis longissiuiis, singula denticulationibus magnis, 

 obtusis, 4; pedibus flavis ?, pilosis, utrinque 43 — 44, postremis valde elongatis; scuto postremo elongato. 



Orange, beautifully polished ; head and appendages deep red ; cephalic segment regularly punctate, regularly 

 narrowed from the front; basal segment and labium smooth; antennas sparsely long pilose; labium strongly emar- 

 ginato, medianly lightly canaliculate; mandibles large, with very long hairs, each with four very large, obtuse 

 denticules ; feet yellow ?, pilose ; on each side 43 — 44 ; last pair very elongate ; last scutum elongate. 

 vol. xni. — 23 



