258 RHYNCHOPHORA. 
MICRORHIANUS, gen. nov. 
Rostrum arcuate; mandibles short, curved, more or less decussate at the tip when closed; head large, 
globose ; eyes narrowly separated above; prothorax conical, tubulate in front ; scutellum very small, 
free; elytra much wider than the prothorax, subtriangular ; pygidium not visible; prosternum unarmed, 
suleate, the sulcus extending backward between the coxee, and limited on each side anteriorly by a slender 
ridge; anterior coxe exserted, narrowly separated in M. hamatus, more distant in JZ. palliditarsis ; femora 
unarmed ; tarsal claws small, connate at the base; body rhomboidal, narrow, polished, glabrous above. 
Type, M. hamatus. 
Microrhianus is based upon two minute forms from Panama, one with a shallow, and 
the other with a deeper prosternal sulcus. ‘They are narrow and somewhat cuneiform 
in shape, and have the upper surface glabrous, the legs slender, the elytra deeply 
striate, &c. 
1. Microrhianus hamatus, sp. n. (Tab. XIV. figg. 15, 15a, 6, ¢.) 
Rhomboid-elliptic, narrow, shining black, the antenne, tip of the rostrum, and tibial claws ferruginous ; 
glabrous above, the short ante-coxal portion of the prosternum densely squamose, the rest of the under 
surface and the legs with small scattered white scales. Head closely, finely punctate, the eyes narrowly 
separated; rostrum strongly arcuate, stout, a little longer than the prothorax, rather coarsely punctate 
at the sides, smoother along the middle, the antenne inserted at the apical third, the antennal club stout 
and ovate. Prothorax slightly broader than long, subconical, strongly constricted in front; with a row 
of rather coarse punctures along the basal margin and another along the subapical sulcus, the rest of the 
posterior portion smooth. Scutellum oblong, sulcate. Elytra arcuately narrowing from a little below 
the base, flattened on the disc, the humeri somewhat swollen; deeply striate, the striae feebly punctate, 
the interstices smooth and flat. Beneath closely, the lateral portions sparsely, punctate, the ventral 
segments 2-4 almost smooth. Prosternum shallowly sulcate. Anterior coxe narrowly separated. Legs 
slender, rather long; anterior tibia armed with a long stout claw, which is fully as long as the first 
tarsal joint and notched at the tip, the other tibie also sharply unguiculate. 
Length 21, breadth 1§ millim. (<¢.) 
Hab. Panama, Volcan de Chiriqui 4000 feet (Champion). 
One specimen. The anterior tibial claw is remarkably developed in this insect, and 
the short anterior portion of the prosternum is so densely squamose that the prosternal 
sulcus is almost hidden. ‘he mandibles are curved, slender and decussate at the tip. 
9. Microrhianus palliditarsis, sp. n. 
Subrhomboidal, narrow, shining black, the antenne, tip of the rostrum, and tarsi ferruginous ; glabrous above, 
the under surface and legs sparsely clothed with minute white scales. Head closely finely punctate, 
faintly foveate between the narrowly separated eyes ; rostrum strongly arcuate, rather stout, a little longer 
than the prothorax, sparsely punctate, the antenne inserted at the middle, the antennal club stout and 
ovate. Prothorax transverse, conical, strongly constricted in front, almost smooth. Scutellum transverse, 
sulcate. Elytra oblong-subtriangular, depressed along the suture at the base, the humeri somewhat 
swollen; deeply striate, the strie feebly punctate, the interstices smooth and almost flat. Beneath 
sparsely punctate, the ventral segments 2-4 with a few scattered punctures only, 1 excavate down the 
middle in the ¢. Prosternum with a deep sulcus, limited on each side by a longitudinal ridge. Anterior 
cox separated by a little less than their own width. Legs rather long and slender; all the tibie with 
a slender claw in both sexes. 
Length 2-21, breadth 145 millim. (¢ @.) 
Hab. Panama, Volcan de Chiriqui 2500 feet (Champion). 
