ite aon Crampton: Sclerites of the Head 87 
and angles formed by the parts of the maxillz in the sawfly larve may 
offer points of value in their classification. 
The galea is divided into a basal segment, or basigalea, ‘“‘bg,’’ and a 
distal segment, or distigalea, ‘‘dg,”’ in the sawfly larvee shown in Figs. 
54 and 49, as is also the case with the galea ‘“‘ga’”’ of the larvee shown in 
Figs. 20, 22, etc. These segments of the galea are apparently homol- 
ogous with the two segments of the galea, “ga,’’ of the beetle shown in 
Fig. 3, and with the structures labeled ‘‘bg”’ and ‘“‘dg”’ in lower insects 
(Figs. 10 and 7). These parts of the galea were designated as the basi- 
galea and distigalea in a paper dealing with the maxille of Orthoptera 
(Crampton, 1916); but Yuasa, 1920, in his paper on the mouthparts of 
the Orthoptera has substituted a terminology of his own for the parts in 
question. Since the designations originally applied to the parts are as 
suitable as those which Yuasa has attempted to substitute for them, 
the original terminology has been retained in the present paper. 
Since the galea, ‘‘ga,’’ of the larva of Corydalis (Figs. 15 and 14) 
is not like that of the adult (“‘ga”’ of Fig. 11) in appearance, and since 
the lacinia, ‘“‘la,” of an adult Corydalis (Fig. 11) cannot be readily 
detected in the larval stages (Fig. 15), there might be some doubt as 
to the interpretation of the parts in the larva and adult. I have there- 
fore included Dr. Craighead’s figures of the musculature of an adult and 
larval Corydalis (Figs. 11 and 14) in order to show that practically the 
same muscles occur in both stages (so far as the type of muscle is con- 
cerned) and furnish an excellent means of determining the homologies 
of the parts. As is shown in Dr. Craighead’s figures, the tentorio- 
cardine muscles labeled “3”’ and “4’’ in Figs. 11 and 14 extend from the 
tentorium to the cardo in both adult and larval stages of Corydalis, 
and the same paragula-cardine muscles bearing the label ‘‘5’’ extend 
from the paragular region to the cardo in both larval and adult head. 
Dr. Craighead states that “the cardo always articulates to the hypo- 
stoma and carries at least two muscles, one (number 3) attaching it to 
the tentorium, and the other (number 5) attaching it to the epicranium.”’ 
The tentorio-stipital muscle labeled “2”’ and the paragula-stipital 
muscle labeled ‘‘6”’ connect the tentorium and paragular region with 
the base of the stipes in both stages. With regard to the muscles to 
the galea and maxillary palpus, Dr. Craighead states that ‘‘the upper 
limit of the stipes, or more correctly, the insertion of its appendages, the 
galea and lacinia, is indicated by muscles ‘‘7’’ and ‘‘8,’’ one attached to 
the base of the galea, the other to the basal joint of the palpi or palpifer 
and extending to the base of the stipes, or occasionally one may go to 
the cardo or a part of it may extend down further to the tentorium.”’ 
It is quite apparent that muscles ‘‘7”’ and ‘‘8” are the same in both 
adult (Fig. 11) and larva (Fig. 14) of Corydalis, so that the structure 
labeled ‘‘ga”’ in Fig. 14 must be the homologue of the galea ‘‘ga”’ (Fig. 
11) of the adult insect, since the same stipito-galeal muscle ‘‘7’’ is 
attached to the structure labeled ‘‘ga”’ in both larva and adult. The 
lacinia, “‘la,”’ of the adult (Fig. 11) is apparently wanting in the larva 
(Fig. 14) of Corydalis, and Dr. Craighead states that ‘‘it (the lacinia) is 
considered to be lacking in most coleopterous: larve. However, in 
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