ON THE Clin.iirnKA OF NORTH AMERICA. 



13 



genus Lithobius; but Mr. Newporl says, that in all Lis specimens of the family the 

 larger depressed surface is a deep elongate oval, whilst the smaller excavations are 

 transverse, oval and furrow-like. We find, among the American species of the Litho- 

 biida?, a group in which the larger surface is scarcely depressed, with the smaller 

 excavations round and almost punctiform. This we have indicated as a distinct 

 genus, with the name of Bothropolys. 



The specific characters of the Lithobiid;v are derived from the number of ocelli, the 

 shape of the dental lamina with the number of teeth, the shape, color and structure 

 of the scuta, &c. The number of the ''yes in the adult is fixed within narrow limits 

 for each species. But when the young Lithobiid emerges from the pi g . 5. 



.it possesses hut a single pair of eyes, besides wanting some 

 of its segments. In the genus Hcnicops, (no! yet discovered in 

 this country,) the single pair of ocelli remain as a permanent cha- 

 racter: but in the other genera the number of eyes are gradually 

 increased until adult life. Mr. New port seems to think the number of labial teeth a 

 good specific character, but we have found it to vary considerably. 



Gen. 1. LITHOBIUS, Leach." 



Antennoe multiartioulatse. Caput latum, complaoatum. Labium aotioe dentioulatum, medium sulcatum, 



emarginatum. Coxae excavationibus magnis, ovatis, serie ud!co in facie d ; 1 a dispositis. (Fii. r . 5.) 

 L. MULTlDENTATi s, .\<w]). — L. brun m us . Begtnento cephalico margine postioo clcvato ; anteiiDis elongatis, 

 spai subsegmeuto impunctato; la minis dentalibus d is tin ids, margine antics fere recto, angiitis 



externis anticis ?ix subproductis, denticulis 12 — I'.t aruoatis; ocellis utrim|ue 32 — ."7; scutorura anti- 

 corum marginibus et posticis ct latcralibus Bed scutorum posticorum lateralibus solum elevatis. 

 L. m 'tis, Newp., Linn. Trans, six. p. 365; fatal, lirit. Mus. Myriapoda, p. 17. 



L. multidentatut, P. Gervaie, Aptercs, iv. p. 236; et Tab!, des Mjriap. (Exp. dans L'Amerique du Sud 



part. Bept. | p 



This species is very similar to Bothropolys nobilis. Indeed the only specific differences 

 noticeable are that this species attains a rather larger size, and lias the anterior margin 

 of the dental lamina straighter, \\ ith the anterior external angle scarcely subproduced. 

 The geographical distribution appears to be identical. Our Arkansas specimen differs 

 slightly from the others, having the external anterior angle of the dental lamina 

 slightly subproduced. The Texan individual has but twenty-six pairs of eyes, but is 

 probably the young of the species. 



'onging to the Smithsonian Institution. 



*Linn. Trans, xi. p. 381. 



