14S THE MTRIAPODA OF NORTH AMERICA. 



Gen. 1. LITHOBIUS, Leach 



Antennae multiarticulatae. Caput latum, complanatum. Labium antice denticulatum, medium sulcatum, 

 emarginatum. Coxarum excavationes magnse, ovatse, in serie unica in facie depressa dispositaa. (Fig. 6.) 



Antenna multiarticulate. Head broad, complanate. Labium anteriorly denticulate, medianly sulcate, emar- 

 ginato. Pits on the coxa large, ovate, arranged in a single series on a depressed face. 



L. American-us. 



" L. ferruginous ; capite magno subquadrato margine postico elevato ; antennis pubescentibus; ocellis nigris 

 Fif;. 6. utrinque 25 — 26; labio complanato, polito, margine fere recto; denticulis 10, parvis, nigris, 



subapproximatis, scutis laevibus, convexis, subquadratis postice rectis; segmento prooanali 

 piloso, pedibus validis flavis spinis validis armatis." 



Ferruginous; head large, subquadrate with the posterior margin elevated; antenna pube- 

 scent; ocelli black, on each side 25 — 26; labium complanate, smooth, its margin almost 

 straight; denticules 10, small, black, subapproximate; scuta smooth, convex, subquadrate 

 posteriorly straight; preanal segment pilose, feet robust, yellow, armed with strong spines. 



L. americanus, Newport, Linn. Trans, xix, p. 305; Catalogue of British Museum (Myriapoda), p. 17. 

 " " P. (.'en; lis, Apteres, iv, p. 236; et Tabl. des Myriap. (Exp. Ameriquc du Sud), p. 29. 



? L. spinipes, Say, Journ. A. N. S., 1st series, vol. ii, p. 108; et in GEuvr. Entom. Ed. M. A. Gory, 1, p. 21. 

 ? L. spinipes, Lucas, Hist. Nat. Anim., Art. iv, p. 543. 

 " L. miltidentatus, Newport," Wood, Journ. Acad. Nat. Sci. 1803, p. 13. 

 " L. americanus, Newport," Wooil, loc. cit. p. 14. 



When I wrote my paper on the North American Chilopoda, I had not a large mass of 

 material at my disposal, and fell into error in my identification of Mr. Newport's species. 

 The characters winch he relies on in separating his L. mnltidentatus and americanus van 

 so much in the two species that the extremes meet, and hence my mistake. The average 

 number of ocelli is greater in 13. mnltidentatus, but individuals occur of L. americanus 

 with :}:$ ocelli, thus coming within the number assigned to multidentatus by Mr. New- 

 port. The diagnosis of the species given above is that of Mr. Newport. The number of 

 ocelli iiiid Labial teeth are too small. 1 would say, ocelli utrinque 26 — 33, denticulis 10 — 

 15. The head and scuta are distinctly but rather sparsely punctate. The alternate small 

 scuta are proportionally very large. The scuta are quadrate or subquadrate. The poste- 

 rior margins of the larger ones are straight, and the angles not prolonged, except in the 

 last two or three, in which the posterior margin is somewhat crescentic. The angles of 

 the Lesser scuta are more prolonged than those of the others. The dorsal surface is not so 



