SILUSA. . 275 
Head small, not more than half as broad as the elytra, rather sparingly and indistinctly 
punctate. Thorax strongly transverse, with a large impression at the base in the middle, 
finely and indistinctly punctate. Elytra short, but longer than the thorax, distinctly but 
not coarsely nor densely punctate. Hind body closely and rather coarsely punctate, 
the punctuation towards the hind margin of each segment more scanty; the punctures 
on the sixth and seventh segments quite as dense as on the basal ones. Hind tarsi 
slender, the basal joint twice as long as the second. 
Of this species four individuals have been found; they do not exhibit any external 
sexual marks. It is an insect that has quite the appearance of S. rubiginosa, and 
apparently agrees pretty closely in most respects therewith, but the mesosternal process 
is a little longer, and more completely separates the middle coxe. 
2. Silusa similis. 
Ferruginea, crebrius longiusque pubescens, antennis fere brevibus, basi apiceque dilutioribus, pedibus testaceis ; 
capite thoraceque obsolete, elytris fortius sed subobsolete punctatis; abdomine haud dense vix fortiter 
punctato. 
Long. 32? millim. 
Hab. GuaTeMaua, Volcan de Atitlan 2500 to 4000 feet (Champion). 
This insect is apparently very closely allied to S. hirtella, but the hind body is more 
finely punctate, and the antenne are shorter and of different colour; these organs have 
the fourth joint rather small, hardly so long as broad, and joints five to ten decidedly 
transverse ; the apical joint is paler in colour than those preceding it, but not in such 
a manner as to form a marked contrast with them. ‘The punctuation of the hind body 
can only be called coarse on the fourth and fifth segments ; both on the more basal and 
apical segments it is but indefinite. In other respects the unique individual is very 
similar to S. hertella. 
3. Silusa vestita. 
Testaceo-ferruginea, longius pubescens, antennis capiteque fuscis, illis basi et articulo ultimo testaceis; elytris. 
abdomineque ex parte tibiisque plus minusve fusco-suffusis ; abdomine irregulariter profunde punctato. 
Long. 33-4 millim. 
Hab. Guatemaa, Volcan de Atitlan 2500 to 3500 feet (Champion). 
Antenne rather short, much thickened towards the extremity ; third joint rather 
elongate, about equal to the second; fourth about as long as broad; tenth rather 
strongly transverse; terminal joint forming a strong contrast in colour with those 
preceding. Head only half as broad as the elytra, sparingly punctate. ‘Thorax strongly 
transverse, twice as broad as long, a good deal narrower than the elytra, rather coarsely 
punctate, and indistinctly impressed towards the base in the middle. Elytra longer 
than the thorax, of vague coloration, the shoulders broadly paler than the other parts, 
sparingly punctate, but with conspicuous pubescence. Hind body with a deep, rather 
2NN 2 
