ON THE CTIILOPODA OF NORTH AMERICA. 37 



" The mandibles are short, thick, and have a distinct basal tooth ; the dental plates 

 are elongated and widely separated; the teeth 8, minute but distinct. The basal joint 

 of the posterior pair of legs much shorter than the second, which is twice as long as 

 the succeeding joints. The lateral anal appendages deeply punctured. Preanal scale 

 flat, with a median longitudinal sulcus and scattered punctures, with the margin 

 .straight." 



We have never seen a specimen of this species. 



Gen. 7. SCOLOPENDROPSIS, Brandt.* 



" Des yeux au nombre de 4 paires ; 23 paires de pieds; stigmates peut-etre cribriforraes ?" 

 Not yet found in N. America. 



Gen. 8. SCOLOPOCRYPTOPS, Newp.t 



Ocelli nulli, segmenta podophora 23, postreniurn angustum ; segrnentutn cephalicura imbricatura. Labium 



edentulum. Antennas 17 articulate. 



S. sexspinosa, Newp. — S. saturate aurantiaca; pedibus flavis, subcompressis; antennis flavis, interdum au- 

 rantiacis, pubesccntibus ; capite labio mandibulis scutis sternisque punctatis; segniento cephalico sub- 

 ovato ; labii margine antico fere recto ; scuto postremo angusto, longo ; pedibus postremis elongatis, 

 baud pilosis, articulo basali tibiali longiore, spina unica magna in superficie inferiore et altera minore 

 mediana in margine superiore interno et rare altera articulari minutissima ; appendicibus analibus late- 

 ralibus valde elongatis, profunde dense punctatis, singula spina apicali unica, alteraque minutissima in 

 angulo superiore posteriore; squama preanali postice vix emarginata. 

 Cryptops sexspinosus, Say, Journ. Acad. Nat. Sci. ii. p. 112, 1821, id (Lequien ed.) CEuvres Entom. i. 



p. 24 ; Gervais, Ann. Sc. Nat. Janv. 1837, p. 51; Lucas, Hist. Nat. Anim. Art. p. 547; Newp., in Ann. 



and Mag. Nat. Hist. xiii. p. 100. 



Scolopocryp. sexspinosa, Newp., Linn. Trans, six. p. 407; Gervais., Apt. iv. p. 297, et Tabl. Myriap. 



Amer. (Exp. Ameriq. du Sud, part, sept.) p. 36. 



In this species the superior spine of the lateral anal appendages is very minute and 

 occasionally present only on one side. The color varies from milk-white to a dark 

 reddish orange. The lighter shades are found in those individuals which have recently 

 shed their skins. The color given in our diagnosis may be considered as that which 

 characterizes the species, being the one at which it finally arrives. The inferior sur- 

 face of the posterior legs is marked with an elongate whitish blotch. The preanal 

 scale is rather short and much narrowed posteriorly. "We have examined a number 

 of specimens, and have found the articular spine but in a few. We recently observed 

 an individual just completing the operation of shedding his skin. This was crowded 

 back so as to cover only the last two or three segments, giving the animal a very 

 peculiar appearance. He soon, however, drew himself out of the old garment with 



*Kccueil, p. 177, 1840. fLinu. Traas. xix. pp. 275. -105. 



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