SYSTEM OF INSECTS. 407 
in the i holer op hagous and saprophagous Lamellicorn ones; 
in the Anoplura and Thysanura; the Chilopoda and 
Chilognatha amongst Apterous insects ; in the Scorpion- 
idea and Aranidea amongst the Arachnida ; and in the 
Macrura and Brachyura amongst the Decapod Crus- 
tacea. Again, in other cases three seems to be the most 
prominent number : this takes place sometimes with re- 
gard to the primary groups of an Order, or what I de- 
nominate the Suborders. Thus we have the Diurnal, 
Crepuscular, and Nocturnal Lepidoptera a ; the Linnean 
genera Blatta, Mantis, and Gryllus constitute the Or- 
thoptcra ; and other instances of this number might be 
produced in some minor groups. But that which ap- 
* Dr. Horsfield, in his very ingenious and generally admirable De- 
scriptive Catalogue of the Javanese Lepidoptera in the Museum of 
the Honourable East India Company, has divided that Order into 
Jive primary groups, apparently to accommodate it to Mr. W. S. 
MacLeay's quinary system. I trust he will pardon me for observing, 
that in this arrangement he seems to me rather to force than to 
follow nature; and that though he adheres to the above system as 
to the number, he forsakes it in the construction of his groups. 
The obvious primary sections of the Lepidoptera, which have 
been evident to almost every one who has at all studied the Order, 
are the three named in the text, corresponding with Li line's genera 
Papilio, Sphinx, and Phalcena. The groups of the last or nocturnal 
section, which Dr. Horsfield has elevated to the same rank with the 
two first, are evidently not of equal value, nor to be placed upon the 
same platform ; for the Bombycidat, Noctuidce, and Phaleenidce, are 
clearly of a secondary rank. Indeed this section is resolvahle into 
more groups of equal value than the learned Doctor has assigned to 
it ; for the Tortricidce, Tincidcc, &c. are not so united to the Geo- 
meters, or genuine nialamides, as to form with them a primary group 
of the Nocturnal Lepidoptera, but are themselves entitled separately 
to that distinction. This will be evident to every one who will take 
the trouble to compare the larvae and their habits, of the two tribes, 
as well as the perfect insects. 
In the construction of his groups, he seems not to have discovered 
in the Lepidoptera a great typical group resolvable into two, or at 
