AMELADUS.—SCIADRUSUS. 171 
AMELADUS, gen. nov. 
Antenne scapo elongato ; cox posteriores late distantes; elytra striis nono et decimo bene discretis. 
This genus is proposed for a more robust insect than the species of Derosomus, and 
at the same time having the body beneath destitute of scales, the eyes are round and 
coarsely facetted, and the ninth and tenth strie of the elytra distinct and uninterrupted. 
The nasal plate is short and has no free margin ; its surface is flat, and exhibits a fine 
sculpture, giving it asilky appearance. The scrobes are visible from above, their lower 
margin prominent and very abruptly defined, their upper margin indefinite. The 
mentum is quite minute and leaves the maxille fully exposed. ‘The first and second 
ventral segments are elongate. The claws are connate, but are larger than is usually 
the case with the connate claws of the members of this group. 
1. Ameladus inornatus, sp.n. (Tab. VII. fig. 8.) 
Sat robustus, piceus, parce setoso-squamosus, setis crassiusculis brevibus vestitus; antennis tarsisque rufis ; 
prothorace rugoso, elytris fortiter seriatim punctatis. 
Long. 54 millim. 
8-93 
Hab. Mexico (Sallé), Jalapa, Matamoros Izucar, Puebla (//ége). 
Antenne only moderately long and slender, first joint of funiculus elongate, much 
longer than the second, club elongate. Rostrum short and broad; head wide; eyes 
convex, circular, coarsely facetted. ‘Thorax moderately broad, rounded at the sides 
and a little narrowed in front, coarsely and deeply rugose, covered scantily, like the 
head, with greyish setosity intermediate between sete and scales. LElytra at the base 
considerably broader than the thorax, with rather large and deep punctures placed in 
rows; sparsely clothed with a greyish and fuscous setosity and bearing short, stout, 
upright setze. Under surface not squamose, clothed with a few fine hairs, 
SCIADRUSUS, gen. nov. 
Elytra humeris sat distinctis ; ale rudimentarie adsunt. 
The species constituting this genus is remarkable in that it possesses small wings 
having veins, but quite useless for purposes of flight; the other characters that are 
correlative with the presence or absence of wings seem also to be in an intermediate 
condition in this interesting insect. The scape of the antenna does not attain the 
thorax; the eyes are slightly angular in outline beneath, the scrobes are lateral and 
form a regular curve quite separated from the eye. ‘The elytra are broader at the base 
than the thorax; the 9th and 10th striz are distinct throughout; the scutellum is 
distinct and is rounded behind; the metanotum is semichitinous; the buccal cavity is 
rather large, the mentum quite small, the maxille being exposed. ‘I'he hind coxe are 
not widely separated ; the first and second ventral plates are elongate, the 3rd and 4th 
much shorter. The body is squamose beneath. 
ZZ 2 
