146 STAPHYLINIDA. 
processes, and are each defined by a fine raised border. When these two borders do not 
meet, I have designated the cavities as incomplete, and the space intervening between 
their extremities I have called the intercoxal isthmus: this intercoxal isthmus is of 
variable length and breadth; but in calling it “long” or “short” I have always used 
the words with reference to its extension in the longitudinal axis of the body. C. J. 
Thomson first began to use, though in a vague manner, these characters; and to M. Rey 
we are chiefly indebted for giving them much greater prominence; but they have not 
yet received all the attention they deserve, and it is advisable that definite terms should 
be used in writing about them. 
Group ALEOCHARINA. 
All the tarsi five-jointed. 
ALEOCHARA. 
Aleochara, Gravenhorst, Col. Micr. p. 67 (1802) ; Erichson, Gen. et Sp. Staph. p. 158. 
I have not thought it advisable for the purposes of this work to adopt the genera 
proposed by Thomson and Rey at the expense of Aleochara, but may state that the 
first three species here enumerated would apparently go into their genus Aleochara, and 
the others, or most of them, into Baryodma, Rey. The genus is nearly cosmopolitan. 
| ° 4. 
1. Aleochara centralis. (Tab. V. fig. 1.) 
Tota nigerrima, nitida, sparsim pubescens; antennis crassissimis, articulis 5°-7™ quam sequentes paulo lati- 
oribus; prothorace minus fortiter transverso, quam elytra fere longiore, basi cum lateribus omnino 
rotundatis ; abdomine parce, fortiter punctato, apicem versus multo angustiore. 
Long. 63-11 millim. 
Hab. Mexico, Jalapa (Flohr); Guaremata, Cerro Zunil 4000 feet (Champion); Costa 
Rica, Irazu 6000 to 7000 feet (Rogers); Panama, Volcan de Chiriqui 2500 to 4000 feet 
(Champion). 
In the male the seventh dorsal plate is nearly truncate, only very slightly emarginate, 
and is furnished with about fourteen very minute teeth or serrations, the ventral plate 
is not at all emarginate; in the female the dorsal plate has the same shape as in the 
male, but is without the serrations, and the ventral plate is truncate, and its hind 
margin is set with very dense pubescence, mixed with which are some longer cilia. 
This species is very similar to the North-American A. lata, Gr., but is undoubtedly 
distinct ; it is of narrower form, more acuminate at the extremity, with considerably 
longer thorax, and has the fifth, sixth and seventh joints of the antenne broader in 
proportion to those following, the hind body less punctate, and the sexual characters of 
the seventh segment different. It is quite as near to the Chilian A. atra, but is larger, 
has much stouter antenn, rather longer thorax, and different sexual structure of the 
seventh segment; an undescribed very close ally exists also in Brazil. 
