Le Conte on the Pselaphide of the United States. 71 
Looking at the contents of this family, as left by Erichson, 
we see much heterogeneous material; Megalops and Osorus 
differ at once by their corneous nilas the latter also by the 
insertion of its antennæ into a very deep cavity. The 
remainder divides itself naturally into two groups: Oxy. gen- 
uini, (Er.) tarsi 3-articulati, palpi articulo ultimo subulato, 
and Oxy. coprophilini, (Er.) tarsi 5-articulati, palpi fili- 
formes. The first of these contains the forms after which we 
were looking; the second being the diverging line to the 
Onalini. Comparing now the Ozytelini genuini with Euplec- 
tus, we perceive a most close agreement in structure as well 
as appearance. ‘The antenna, feet, and sutures of the thor- 
acic segments are all similarly situated, while the relations 
between the parts of the mouth are identical. In the genus 
Faronus, (although furnished with two claws,) we perceive 
other Oxyteloid characters, in the shortening of the second 
tarsal joint, and the stracture of the abdomen. 
We have now got a large group containing Pselaphi, Scyd- 
meni, and Orytelini, which seem from the affinities just men- 
tioned, to be very closely related. To circumscribe this group, 
and to discover its higher forms, (if any exist,) is a work of 
much labor, and could be undertaken only after a careful 
study of all the groups of Coleoptera, and a knowledge of 
their larvee. Although much labor has been given to the lat- 
ter subject, our information is still too imperfect for general 
Systematic inquiries. Since the Coleoptera have heretofore 
been studied for the purpose of being arranged into groups 
rather than series, many characters used in defining these 
groups must be rejected, when we attempt to find the rela- 
tions of these to each other. (Vide note on page 68.) 
In fact, a too strict. adherence to characters indicating 
States of development, has already led to the formation 
of two very heterogeneous tribes, the Brachelytra and Heter- 
omera : the latter containing many embryonic forms, known 
by their Softness, and imperfect structure, while the former is 
a general receptacle for all larval forms with a corneous abdo- 
