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 pseadacacia, L.) I have, however, occasionally observed them under stones. It may possibly be Geophilus attenuatus, but that species can never be determined from Say's description.
M. melanonotus.
M. parvus, gracilis, dilute aurantiacus; lineis duabus dorsalibus, latis, nigris, e capite ad segmentum penultimuin ductis; capite sparse breve piloso; antennis sparse pilosis; labio, medio valde canaliculato, utrinque maculis tribus nigris; mandibulis intus vix denticulatis; lateribus nigro maculatis; scuto post re mo dilute aurantiaco; 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; antennæ sparsely pilose; labium medianly strongly canaliculate, on each side, with three black maculæ; 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 punctato, a fronte ordinatim angustato, segmento basali labioque lævibus; antennis sparse longe pilosis; labio valde emarginato, medio leviter canaliculato; mandibulis magnis, pilis longissimis, 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; antennæ sparsely long pilose; labium strongly emarginate, 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. xiii.—23
