472, STAPHYLINIDA. 
Only one example has been procured in our region, and it may ultimately prove to 
be distinct from the South-American P. formicarius; but at present it must be 
treated as a variety of a variable species. 
3. Plochionocerus debilis. 
Minor, elongatus, nigro-eneus, subnitidus; abdominis apice rufo, capite suboblongo, dense fortiter punctato, 
opaco; thorace minus gracili, crebre subtiliter punctato, subnitido, linea mediali lavigata; elytris thoracis 
longitudine, crebre subtiliter punctatis, sat nitidis ; capite subtus densius fortiter punctato. 
Long. 12 millim. 
Hab. Guatemata, San Gerénimo and San J oaquin in Vera Paz (Champion). 
Antenne stout, black, a good deal thickened towards the extremity. Thorax broad 
(for this genus), but a good deal narrower than the elytra. Last segment of the hind 
body red. 
This is the smallest species of the genus, and should be placed after P. minor, from 
which it is distinguished by its smaller size, more parallel form, by the red extremity of 
the hind body, and slight differences in the sculpture of the different parts of the body. 
Only one example was met with in each locality. 
HOMALOLINUS. 
Corpus depressum, fere levigatum, capite angulis posterioribus haud rotundatis, medio canaliculato (canalicula 
antice bifurcata) utrinque sulcula curvata breviore, collo perabrupto angusto. Labrum late emarginatum 
longissime ciliatum. Palpi graciles, elongati, articulo ultimo quam precedens longiore. Tarsi anteriores 
graciles. Prothorax anterius in medio rotundatus, linea laterali superiore subtus abrupte sinuato-deflexa ; 
prosternum magnum, haud carinatum. 
This genus is proposed for Xantholinus canaliculatus, Er., and allies; it should be 
placed near Nudobius, from which it departs by the sculpture of the head, the much 
more elongate trophi (the difference as to the terminal joint of the labial palpi in the 
two being very great), and also by the fact that the superior marginal line of the thorax, 
notwithstanding its great deflection, does not reach the inferior line, but remains quite 
separate from it even at the front of the coxal cavity. 
The different species live under bark of trees; and the genus seems specially charac- 
teristic of our region, one species extending its range to Rio de Janeiro. 
1. Homalolinus canaliculatus. (Tab. XII. fig. 17.) 
Xantholinus canaliculatus, Er. Gen. et Spec. p. 307°. 
Hab. Mexico1, Cordova, Tuxtla (Sallé), Jalapa (Flohr, Hoge), Cerro de Plumas 
(Hége); Guatemata, Capetillo, Cerro Zunil, Las Mercedes (Champion); Costa Rica, 
Cache, Irazu 6000-7000 feet (Rogers); Panama, Volcan de Chiriqui up to 6000 feet, 
Tolé (Champion).—Sovtu America, Colombia 14, Brazil. 
This species is found under bark of dead trees, and I have a fine series before me 
