Hardenberg—Studies in the Trophi of the Scarabaeidae. 553 
nent in Coleoptera and is in Scarabaeidae usually helmet- 
shaped or spatulate. It is composed of two segments, hut this 
condition is obscured in most of the Scarabaeidae. 
The lacinia or blade (inner lobe, inferior lobe) is borne on 
the inner margin of the sub-galea. It is claimed to be the 
cutting part of the maxilla (1), but it is generally its weakest 
point and can be only secondary in importance for the above 
mentioned purpose, since it follows the galea in its chitiniza- 
tion. In Scarabaeidae it is often provided with a hairy fringe 
at the tip, the hairs being used as stiff brushes in the pollen¬ 
eating forms. 
Sometimes the lacinia bears at its distal end a small append¬ 
age, the digitus, which in some cases has the form of an artic¬ 
ulated claw, as in Cicindelidae. It was found only in a few 
species of Scarabaeidae. 
The function of the mandibles seems to be two-fold, viz.: 
they act as accessory jaws in grinding and cutting the food, 
and they are also used for seizing and retaining the food in 
the mouth whereby the palpi act as fingers. Whether or not 
the palpi contain organs of smell has not yet been settled de¬ 
cisively (7). 
The labium or under-lip (second maxillae of Packard). 
This organ is formed by fusion at the basal portion of sepa¬ 
rate embryonic appendages, which arise in the same manner as 
the first maxillae, as appendages of the last or occipital seg¬ 
ment of the head. The parts, although fused to a consider¬ 
able extent, can be homologized with the parts of the maxillae. 
The labium consists of gula, sub-mentum, mentum, palpigers 
with the palpi, iigula and paraglossae; on its upper side we 
find the hypopharynx. 
There is a great diversity of opinion among different au¬ 
thors about the homologies of these parts, and the terminology 
is very confusing. In the typical labium we find, starting 
from the posterior end, the gula (supposed to be the ventral 
plate of the occipital segment of the head), the sub-mentum 
and the mentum with its palpi and lobes. The mentum is 
often so small that it is concealed by the sub-mentum; on ac- 
