168 RHYNCHOPHORA. 
American Otiorhynchide would, I think, nearly correspond with that I have used for 
the forms found in our region. 
DEROSOMUS, gen. nov. 
Antenne scapo valde elongato, tenuissimo ; coxee posteriores late distantes; abdomen segmento secundo ven- 
trali tertio longiore. 
Form elongate and slender; with long, very slender antenne, whose scape extends 
back on to the front of the prothorax. Rostrum not dilated at the tip; nasal plate 
elongate, with slightly elevated margin. Lower border of the scrobe very definite, 
the lateral border rapidly descending at a considerable distance in front of the eyes, 
the upper border indefinite, but defined by the scales. Eyes oval, only moderately 
prominent. Mentum very small, leaving the maxille exposed at its sides and all the 
palpi visible. Scutellum small, acuminate. Metanotum short, semimembranous; wings 
absent. Metasternum moderately long. Hind cox widely separated. Lateral edge of 
the elytra very strongly sinuate, the tenth series of punctures quite indistinct. First 
ventral suture nearly straight ; third and fourth ventral plates rather long. 
The facies of the species of this genus is quite that of the European Eusomus ; but in 
Derosomus, and indeed in all of the Sciaphilina of our region, the femora are unarmed. 
Horn’s description of Mitostylus («N. Am. Rhynchophora,’ p. 107) seems to indicate 
with certainty that it is an apterous form; but I doubt very much whether Derosomus, 
or any of the genera I describe below, will prove to be congeneric with it. 
1. Derosomus fragilis, sp.n. (Tab. VII. figg. 5, ¢; 5a, front tibia.) 
Gracilis, piceo-niger, griseo-squamosus, fusco-subfasciatus ; antennis testaceis, scapo apice clavaque fuscis ; tibiis’ 
fusco-testaceis. 
Long. 5-6 millim. . 
Hab. Mexico, 'Temax in North Yucatan (Gaumer). 
Covered with pallid fine scales which conceal the sculpture, but without sete. 
Antenne very slender ; second joint of funiculus scarcely longer than the first. Thorax 
about as broad as long. LElytra slender, oblong-oval, with series of large punctures 
concealed by the clothing ; this is of a pale colour, but there are one or two irregular 
transverse fascize darker. Male with the front and middle tibie dilated towards the 
extremity, and with a very large excision on the inner side. 
Gaumer obtained a large series of this species; it is variable in colour, the scales 
in some examples being strongly tinged with green. ‘The absence of sete and the 
peculiar tibiee of the male distinguish the species very satisfactorily from its congeners. 
2. Derosomus setosus, sp. n. 
Pallide griseo-squamosus, fusco-subvariegatus, setis elongatis erectis vestitus ; antennis fusco-testaceis. 
Long. 53 millim, 
