ARCANA NATURÆ. 127 
zona and New Mexico, and is figured by me in Smithsonian contributions, XI, in a memoir on the 
Coleoptera of Kansas and New Mexico. 
I formerly included in this genus Meloe cancellatus, Br. and Er., and C. vittatus, Lee. [Proc. Acad., 
VI, 330), which differ by the elytra being mueh shorter than the abdomen and diverging, though not 
imbricate as in Meloe. The ungues are armed with a tooth as in Cysteodemus. I now, however, fully 
agréé with the opinion ofLacordaire [Gen. Col., V, 660), that they should form a new genus, for 
which I propose the name Megetra. 
MALLODON. Serv. 
17. M. STS.KKVLX 1 VS, piceo-niger nitidus, capite antice parcius, pone oculos densius punctato, genis sub- 
acutis; thorace transverso, lateribus scabro et inœquali, disco subtilius parce punctato, antrorsum sub- 
angustato, lateribus redis serrulatis, versus angulos posticos paulo reflexis; elytris disperse subtilius 
punctatis.^- Long. 70 mill. — Tab. XIII, fig. 5. 
Leconte, Proceedings ofthe Academy of Natural Sciences of Philadelphia, VII, 82. Texas, lhis spe- 
cies resembles M. cilipes, Hald. (Prionus cilipes, SayJ, but the sides of the thorax are less serra te and 
less reflexed ; the dise is less convex ; the mandibles are similar to those of that species, not elongated, 
but thick and emarginate at the apex. 
STENASPIS, Dup. 
18. S. splendens, nigra, thorace latitudine breviore, subinœquali, irregulariter vnodice punctato, 
plagis lœvibus relidis, postice magis constrido tuberculo laterali obtuso ; elytris viridi-œneis nitidis, 
rugis profundis parcis intricatis, interstitiis elevatis convexis parce pundulatis ; femoribus Iwte auran- 
tiacis basi apieeque nigris antennis nigris, extrorsum rufescentibus. — Long. 35 mill. — Tab. XII, fig. 9. 
Leconte, Proceedings ofthe Academy of Natural Sciences of Philadelphia, VI, 441. Texas. Resembles 
in color and form S. verticalis, Dup., but the thorax is entirely black, and the posterior constriction 
is much deeper; the very deep confluent rugosities of the elytra at first sight distinguish it. 
19. S. solitaria, Lee. (Cerambyx solitarius, Say) varies in having the head, thorax and anterior 
part of the elytra reddish brown ; it differs from both species above mentioned by the latéral tubercle 
of the thorax being more acute and the anterior tubercle more prominent, as well as by its black 
color. 
ARHOPALUS, Serv. (emend., Lee. J. 
20. A. eurystethus, ferrugineus, subtus dense pallide sulphureo-pubescens, thorace fusco, dense sul- 
phureo-pubescente, transverso, ad basin declivi, lateribus rotundatis ante basin angulatis ; elytris fuscis 
piceo-pubescentibus, fascia lata dentata ad quadrantem, linea angulata ad medium, fascia lata pone 
medium et linea angulata pallide sulphureis ornatis, ad apicem singulatim longe acuminatis ; pedibus 
late distantibus, prosterno postice subprodudo, late subtruncato. — Long. 20 mill. — Tab. XIII, fig. 9. 
Leconte, Proceedings of the Academy of Natural Sciences of Philadelphia, 1858, p. 82. Arizona. 
The latéral angle of the thorax is sometimes distinct, sometimes indistinct, never acutely prominent as 
in A. erythropus. This species belongs to a group in which the anterior feet are widely separated, the 
prosternum broadly and slightly produced posteriorly, and the mesosternum sucldenly declivous in 
front, thus exhibiting a tendency to Megaderus, which with the Trachyderides should immediately 
follow this group in a natural arrangement. 
