STENUS. 641 
undoubtedly well represented in tropical as well as in temperate countries, the lowest 
estimate that I can make of the number of its species is 1500; it is found in nearly all 
parts of the world, except oceanic islands and New Zealand. It was proposed by 
Motschoulsky, and more recently by Casey, to separate the genus into two, leaving the 
name to those species having filiform tarsi; this course, however, is premature, and the 
genus when divided will probably fall into many more than two. Rey has very recently 
proposed six subgeneric names for the European species, but his divisions are not 
happily selected; and as Erichson’s main sections of the genus, depending on the 
lobation or simplicity of the tarsi and the margined or immarginate hind body, are 
quite satisfactory, I make use of them, adding a few subordinate groups where necessary 
to facilitate the determination of our species. These, as will be seen, are fairly 
numerous, though falling far short of the corresponding number of species in North 
America, from which region Casey has recently described no less than 170. The 
species of our country seem, as a rule, to be less gregarious in their habits than those 
of more northern regions. I have no doubt that further researches will more than 
double the number of Central-American species. The Stent of our region show appa- 
rently but little relationship with those of North America, and it is probable that, 
except in the northern parts of Mexico, very few species indeed are common to the two 
regions. Our species are much more similar to those of the Amazon valley and other 
parts of South America, but as yet very few appear to be common to it and to the 
South-American continent. I here register 66 species as found in our region. 
I. Tarst articulo quarto simplice. 
A. Abdomen marginatum. 
1. Stenus renifer. (Tab. XVII. fig. 2.) 
Stenus renifer, Lec. New Sp. Col. p. 50*; Casey, N. Am. Stenini, p. 16 *, 
Hab. Norra America, Fort Yuma}, Texas ?.—MEeExico (Mohr). 
2. Stenus sallzi. 
Elongatus, angustus, subopacus, niger ; abdomine minus opaco, brevissime griseo-pubescente ; palpis flavis, 
antennis pedibusque fusco-testaceis ; dense rugoso-punctatus ; prothorace obsolete canaliculato; elytris 
minute vix perspicue flavo guttatis. 
Long. 53 millim. 
Hab. Mxxico, Guanajuato (Sallé). 
Antenne rather long, with ‘slender club, each joint of which is considerably longer 
than broad. Head excessively densely sculptured, the sculpture consisting of minute 
rugosities ; the interocular grooves are extremely obsolete, the space between them less 
than the lateral space. The thorax is considerably narrowed in front and behind, the 
greatest width slightly in front of the middle ; the rugose sculpture is deep, rather fine, 
BIOL. CENTR.-AMER., Coleopt., Vol. I. Pt. 2, November 1886. 4 NN 
