116 HETEROCERID 2. 
Hab. Mexico, Cordova (Sallé). 
Head rather finely punctate, shining. Thorax also shining, not closely, and mode- 
rately coarsely punctate. The strie on the elytra are at the base scarcely impressed, 
and consist there rather of simple series of moderately large punctures. 
I have seen only two specimens. 
Fam. HETEROCERIDA. 
HETEROCERUS. 
Heterocerus, Fabricius, Ent. Syst. i. p. 262; Kies. Naturh. Zeit. iv. p. 1945" Linn. Ent. v. p. 281. 
The single genus Heterocerus is itself nearly the same thing as the family Hetero- 
ceride; for in addition to Heterocerus there is but a single (Australian) species that 
can be assigned to the family. Heterocerus is a genus of wide distribution, occurring 
throughout the continents of the eastern hemisphere and in Australia, while in the 
New World there are numerous species in North America. They are small insects, 
living in burrows in mud and sand in the immediate neighbourhood of water ; and it is 
probable that the species are much more numerous than the seventy or eighty at 
present described. ‘To the peculiar habits and unattractive character of these insects 
is probably due the fact that only one or two species have yet been described from 
South America; a like small number are known from the Antilles. ‘The species of the 
genus, even in the most distant regions of the world, are singularly like one another in 
size and other details from which the specific characters of Coleoptera are usually 
drawn; and the study of the genus is thus a matter of considerable difficulty, and will 
of course become still more difficult as the record of species becomes more complete. 
Schiddte, a few years ago, pointed out (Nat. Tidss. 1866) some characters by the aid of 
which the European species may be grouped satisfactorily ; and in studying the species 
here enumerated I have observed another character that will be of further assistance : 
this is the existence in certain species (European and North-American as well as 
Central-American) of a curved raised line proceeding outwards from the middle of the 
lower border of the intermediate coxal cavity and connecting it with the epimeral suture 
in such a manner as to form, in combination with the hinder part of this suture, a 
raised curved elevation of considerable length. The position of this curved line in 
relation to the middle femur is such as to suggest that it might prove to be a portion 
of a stridulating-organ, like the curved elevation on the first ventral segment of these 
insects; but I can find no further grounds for considering this to be probable. 
1. Heterocerus debilis. (Tab. IV. fig. 3.) 
Minutus, angustulus, sat elongatus, testaceus, capite fusco, subtilissime punctatus, pube tenuissima vestitus, 
opacus ; prothorace convexiusculo, angulis posterioribus immarginatis; tibiis anterioribus spinulis cras- 
siusculis armatis. 
Long. 1, lat. 3 lin. 
