24 ON THE CHILOPODA OF NORTH AMERICA. 



We have a specimen from Mexico, which perfectly agrees with Saussure's descrip- 

 tion of his S. olomita, and also with our other specimens of S. morsitans. 



Specimens belonging to the Smithsonian Institution. 



Probably incorrectly labelled. 

 S. otomita, Saussure. 



360 



1 



'/Halifax, N. S. 



Dr. J. B. Gilpin 



352 



1 



La Union. 



Capt. Dow. 



333 



1 



Miuititlan. 



? 



Unc 



24 



it 



34 



u 



4 



Var. )3. — S. luteo-castanea, gracillis, pedibus flavis compressis; capite laeve, irnpunctato, seguiento-cephalico 

 elongato, ovato, subsegmento prebasali nullo, segmento basali magno; labio mandibulisque sparse minute 

 punctatis; scutis (postretno excepto) plerutuque postice truncatis et margine postico saturate viridi ; 

 antennis 22? articulatis, flavis; laminis dentalibus margine antico rotundato ; dentibus 19 parvis, 

 utrinque tribus intimis arctissime coadunatis, externo sejuncto; pedibus postremis magnis, robustis, 

 supra complanatis, subtus valde convexis, articulo basali marginibus superioribus acutis sed baud elevatis, 

 intus 4 — 5 spinis, subtus 8 — 9 spinis in serie triplici dispositis, processu angulari elongato 3 — 1 spinis ; 

 articulo tibiali marginibus superioribus subelevatis ; appendicibus analibus lateralibus profunde punc- 

 tatis, brevibus, singula spinis 3 — 4 apicalibus et altero marginale. 



Length of cephalic segment rather great in proportion to its width. Basilar seg- 

 ment large. Lateral margins of most of the scuta straight ; only those of the last five 

 or six elevated. Throughout the whole length of the body there is a tendency to the 

 alternation of a larger with a smaller scutum. Preterminal scutum large, with its 

 lateral margins strongly arched, but its posterior straight. Terminal scutum large, 

 marked with a median line; its breadth one-third greater than its length, equalling 

 that of the basal joint of the last pair of legs. Sterno, episternal and scuto episternal 

 sutures well marked. Inferior surface of basal joint of posterior pair of legs with 

 from 8 — 9 spines in three rows, the external of which (in our specimen) is composed 

 of two spines. Mr. Newport was at a loss to decide whether this was a distinct 

 species, or merely a variety of S. morsitans. We are disposed to believe it different 

 but have not seen enough specimens to decide. The principal differences between our 

 specimen and those from this continent are, firstly, the margins of the basal joints are 

 not elevated ; secondly, the labial teeth are much smaller. 



Specimens belonging to the Smithsonian Institution. 

 250 | 1 | Simoda, Japan. | Nortb Pacific Expl. Exp. | W. Stimpson, M. D. | Unc. 2± \ 



S. iNiEQUiDENS, Gervais. — S. viridi-brunnea; segmento-cephalico punctato, parvo, basali magno postice sub- 

 truncato; antennis interdum viridibus, pubescentibus, 17 articulatis; labio mandibulisque sparse sub- 

 profunde punctatis ; laminis dentalibus elongatis ; dentibus 6 — 8, utrinque intimis duobus arete coadu- 

 natis, duobus externis scjunctis, acutis; scutis interdum postice saturate viridi aut cseruleo marginatis; 

 pedibus lutcolis, gracillibus, longis; postremis robustis, articulo basali supra subconvexo, intus 3 — 8, 

 subtus 7 — 10 spinis; processu augulari 2 — 6 spinis; appendicibus analibus lateralibus dense pro- 

 fundeque punctatis, elongatis, spinis apicalibus 3 — 5. 

 S. iniequidens, Gerv., Apt. iv. p. 277. 



The cephalic segment is small, truncate posteriorly, and has its sides remarkably 

 straight. The basal segment is very large, fully half again as broad as the cephalic. 



