INTRODUCTION. 
85 
JEgocerides , &c. That of Crepuscular is adapted 
more or less to some sphinges, but by no means to the 
Zygenid.es , which fly only in the heat of the sun. 
Finally, the term Nocturnal is not more properly 
applicable to all the species, since many belonging 
to this section appear only during the day. In order 
to avoid these improper denominations, we have 
substituted for the word Diurnal , that of Rhopalo- 
ceres, proposed by M. Dumeril. Being unable to 
perceive limits between the Crepuscular and Noc- 
turnal divisions of Latreille, we have united those 
two great sections under the name of Heteroceres. 
In our method, therefore, the lepidoptera are di- 
vided into two grand legions, Itkopaloccres and 
Heteroceres*." 
Dr. Boisduval then proceeds to explain that the 
first of these divisions is characterised by antennas 
thickening to a club at the extremity ; and the se- 
cond, by having these organs variously shaped; this 
indeed is implied by the words themselves. The 
first division is subdivided into three sections, ac- 
cording to the manner in which the caterpillars 
transform themselves into chrysalides. Such as un- 
dergo this change by attaching themselves by the tail 
and a band round the middle, form the first division, 
named Succincli ; such as are suspended by the tail 
only, the second, Penduli ; while those which form 
a cocoon by rolling leaves together, compose the 
third division, termed Involuli. 
Species gdndral des Lepidopteres, p. 158. 
