1878. | 573 {Horn. 
This tribe differs from the preceding in the greater length 
of the first three tarsal joints and the comparatively smooth 
and glabrous surface of all the species. The difference 
founded on the greater length of the first abdominal seg- 
ment is illusory. 
The following genera occur in our fauna: 
Anterior cox narrowly closed behind, prosternum at tip attaining the 
(OOS KCINKOW WIEN tlas SWeemdodcoLeons Soo comeD oboe Group COLYDII. 
Metasternal side pieces moderate. Anterior tibiz finely denticulate at 
GUICr DMeA AINE S sonata oo ronocemen ne Gaoee aon 6 dnuoe Aulonium. 
Metasternal side pieces linear. Anterior tibize with outer apical angle 
[KONGERS < GeOn Ho Goo AO Ca oUOOatian: On oe org SapmeacaD ofr Colydium. 
Anterior cox broadly closed behind, the epimera meeting on the median 
line, prosternum not attaining the margin....Group NEMATIDII. 
Metastemnal side pieces GOVeEre dl. ac206% 9 5 «siete <= moe cisvele =) <1 21s Nematidium. 
Anterior cox open behind. Head without eyes........ Group AGLENT. 
Mefasternall sige pieces Marrow «ote « <ts ss die) ais: oie, ofela\sl sree 'sis oim's oth Agilenus. 
It is possible that the groups above indicated should be 
raised to the rank of tribes with the introduction of foreign 
genera. The most curious character presented by any of the 
above genera occurs in Nematidium, in which the arrange- 
ment of the posterior margin of the thorax beneath repro- 
duces the normal structure of the Rhynchophora. This char- 
acter was observed by me in 1870, while seeking for allies 
of Cossyphus in the present family, the latter having a simi- 
lar sternal structure. 
Awlonium is the only genus with representatives on both 
sides of the continent, although our one species of Colydium 
extends to Vancouver. Nematidium occurs only in the 
Southern States, while Aglenus has probably been intro- 
duced. 
AULONIUM Erichs. 
Antenne eleven-jointed, club rather Joosely triarticulate, inserted in 
front of the eyes under the expanded frontal margin. Eyes moderately 
prominent, rather coarsely granulated, emarginate in front by the sides of 
the clypeus. Anterior cox not widely separated. Posterior cox sepa- 
rated by a triangular acute abdominal process. Anterior tibiz serruiate 
at outer apical angle and with two spurs, the anterior larger and arcuate. 
Tarsi with the first joint moderately elongate especially the middle and 
posterior, clothed beneath with moderately long hair. 
