RHYPORIUS. 125 
with the pygidium sometimes exposed. Antenne geniculate, 11-jointed—1 very long and robust, much 
recurved, 2 ovate, more than one half shorter than 1, 3 small and slender, 4 very short, transverse, 5 more 
than twice as large as 4, 6 very short, transverse, 7 very large and much incrassated, as long as the four 
preceding joints united, 8 short, transverse, subtriangular, 9-11 forming a moderately incrassated club. 
Palpi: masillary very large, 4-jointed—1 very small, 2 very long, and very large, subcylindrical, faintly 
incuryed, rather widest near the base, 2 very short, transverse, 4 semioval, clothed with short hairs ; 
labial large and robust, 3-jointed—-1 very small, 2 large, rather pyriform, broadly truncate at the apex, 
3 moderate, truncate, and furnished with short hairs at the apex. Mentum subquadrate, short, slightly 
rounded at the sides. Labiwm long and broad, rounded at the sides. Lingua moderate, subtriangular. 
Labrum small and short, ovally rounded in front. MJandibles linear, very long and slender, deeply bifid 
at the apex, with the points widely divergent and terminating in a very acute strong hook. Mazille 
unilobed ; lobe very long and robust, very acute and simple at the apex. Prosternum very short, elevated 
between the coxee, and much dilated behind them; episterna minute, scarcely perceptible; epimera very 
narrow, narrowly enclosing the coxal cavities ; coxal cavities rather large, oval. Mesosternum very short; 
episterna rather small; epimera large and long, not extending to the coxal cavities; coxal cavities large, 
rounded, moderately distant. Metasternum rather short, not extending to the sides of the body ; episterna 
large and broad, longer than the metasternum; epimera long, concealed by the elytra; coxal cavities 
large, pyriform, not reaching to the sides of the body, the margin of the metasternum straight between the 
coxee. Venter composed of six segments—1 long, but scarcely as long as the metasternum, 2-6 nearly 
equal to each other in length, the apical segment simple. Legs long and very robust: anterior with the 
trochanters very small, triangular; femora robust; tibize generally more or less dilated; tarsi 4-jointed— 
1 and 2 large, broadly bilobed, and pilose, 8 exceedingly minute, 4 long and robust; claws rather long, 
unidentate beneath ; intermediate similar to the anterior, but longer, with the tibiz dilated before the 
apex; posterior similar to the intermediate, but longer, with the femora much more robust. Cowe: 
anterior separated by the prosternum ; intermediate moderately distant; posterior more widely separated 
- than the intermediate. 
Rhypobius resembles some of the Byrrhide in appearance, and is on that account 
easily recognizable. The sixth joint of the antenne, and the third joint of the tarsi, 
can scarcely be discovered without the assistance of Canada balsam. 
This genus was founded by Leconte upon a single species from Coney Island, and I 
have recently described another from Europe; a third inhabits Guatemala. 
1. Rhypobius guatemalensis, sp. n. 
Ovalis, validissime convexus, nitidissimus, castaneus ; capite parvo, vix conspicuo; pronoto sat magno, leviter 
remoteque punctato, interstitiis leviter alutaceis, antice leviter excavato, lateribus circulariter rotundatis, 
leviter marginatis, margine basali leviter sinuata, scutellum versus parum producta, angulis acutis, parum 
productis ; elytris modicis, quam caput atque pronotum longioribus vix latioribus, pone humeros latissimis, 
magis profunde punctatis, interstitiis alutaceis, lateribus leviter marginatis, apice obtuso; antennis longis, 
robustis atque pedibus flavis. Long. corp. 7% lin.=0°75 millim. 
Head very small, scarcely exserted; eyes small, not prominent; antenne long and robust, yellow. Thoraw 
rather large, faintly and distantly punctured, with the interstices faintly alutaceous, slightly excavated in 
front; sides circularly rounded and faintly margined; basal margin feebly sinuated, rather produced 
towards the scutellim, with the angles acute and slightly produced. Scutellum rather long, rounded. 
Elytra moderate, longer but not broader than the head and thorax, widest below the shoulders; more 
deeply punctured than the thorax, with the interstices more strongly alutaceous ; sides slightly margined ; 
apex obtuse. Legs moderate, yellow. Underparts castaneous. 
Hab. GuatEMALA, near the city (Champion). One specimen. 
Differs from R. marinus, Lec., in its much smaller size and perfectly oval form, and 
also in sculpture. 
