90 Annals Entomological Society of America [Vol. XIV, 
articulates with this region is called the epicondyle, or dorsal condyle 
of the mandible. A ventral condyle of the mandible called the hypo- 
condyle articulates in an acetabulum or groove of the hypostomal region 
of the under side of the head. Comstock and Kochi, 1902, use the 
terms dorsal and ventral articulations of the mandible in the opposite 
sense from that employed here; but it is more logical to refer to an 
articulation which is on the dorsal surface of the head as the ‘dorsal 
articulation of the mandible,’’ and the articulation which takes place 
on the ventral surface of the head as the ‘“‘ventral articulation of the 
mandible,’’ without reference to any supposed original position of the 
sclerites involved in these articulations. 
The hypopharynx, in the broad sense of the term, includes not only 
the median tongue like organ or lingua, which projects from the floor 
of the mouth cavity, but also the paragnaths (called “‘superlinguze’’ and 
“‘paraglosse’’), or lobe-like structures on either side of the median 
tongue, in such insects as Hemimerus, immature ephemerids, etc. 
Since the median tongue-like lingua is usually the only portion of the 
hypopharynx to be retained in certain insects, the term hypopharynx 
is usually applied to the lingua alone. The lingua is formed by the 
sternites of the labial, maxillary and mandibular segments, according 
to the embryological investigations of Heymons, Holmgren, and others; 
and a study of the Crustacea would indicate that this view is the correct 
one, since a ridge which is apparently the forerunner of the lingua of 
the hypopharynx of insects, is formed in the sternal region of the 
mouthpart segments of certain Crustacea. 
The paragnaths (‘‘superlinguz’’) or lobe-like structures on either 
side of the median tongue or lingua of the hypopharynx of insects are 
clearly the homologues of the paragnaths of Crustacea, as may be seen 
by comparing the structures in question of an immature mayfly with 
the paragnaths of Crustacea such as Asellus, various Isopoda, Amphi- 
poda, etc., (see article in Psyche, 1921) so that it is preferable to apply 
to these structures of insects the term applied to their homologues, the 
paragnaths, in Crustacea, instead of employing the term ‘“‘super- 
linguz’’ or the incorrectly applied term “ paraglossze’’ (which should be 
restricted to the labial structures of this name) for them. The par- 
agnaths of Crustacea are apparently detached lobes of the first maxilla 
which take up a position behind and slightly mesal to the bases of the 
mandibles in the higher forms; but in Apus and other primitive 
Crustacea, they are evidently lobes of the first maxilla. It is wholly 
incorrect to homologize the paragnaths of insects with the first maxillee 
(maxillule) of Crustacea, and to homologize the first maxille of insects 
with the second maxilla of Crustacea, as is done by practically all 
recent investigators, since the paragnaths of insects are in every way 
homologous with those of Crustacea, and the first maxilla of insects 
represent the first maxille (not the second maxilla) of Crustacea, as 
has been shown in an article in the Transactions of the Entomological 
Society of London, 1921, and in an article which will shortly appear in 
the Proc. Ent. Soc. Washington, 1921. 
