FOLSOM: MOUTH-PARTS OF ANURIDA MARITIMA. 195i: 
to correspond with the adjacent convex surfaces of the first maxille, as 
in the adult (Plate 7, Figures 44, 45, ehé.), and each ventro-lateral edge 
extends under the neighboring maxilla; in addition, the apex of the 
lingua becomes separated into two lateral lobes by a median sinus, and 
the dorsal surface invaginates to form a median longitudinal groove 
(Plate 7, Figure 42, sud.) ; this lobed condition, however, is quite 
secondary in origin. 
The lingua is thickly chitinized, and the hypodermal cells persist in 
the mature organ. The superlinguz, on the contrary, are but thinly 
chitinized and at maturity contain no distinct hypodermis cells, except 
basally, although a complete layer of cells exists in Stage 8. In this 
stage (8) the superlinguz become triangular in cross-section, as in the 
adult (Plate 7, Figure 44). Partly on account of the divergence of 
the superlinguz in front, but principally owing to the convergence of 
the mandibles and maxille, the attenuated distal part of each superlingua 
becomes situated between the apices of the mandible and the first 
maxilla of the same side (Figure 44), and the superlinguze conform to 
the adjacent surfaces of the maxille. 
The most interesting lingual structures are the two basal stalks 
(Plate 6, Figure 38, pd.'), each of which articulates with the cardo of 
the same side and also furnishes a firm origin for the adductors and re- 
tractors of the first maxilla, as in Orchesella (Folsom, ’99, Plate 3, Fig- 
ure 21). The development of these stalks has never been described. 
Although difficult to comprehend with a knowledge of the finished con- 
dition only, it is simpler than might be expected. The key to the 
understanding of its origin is the fact that each chitinous stalk is formed 
in a groove which is but a longitudinal evagination of the maxillary 
pocket, and follows the mesal surface of the first maxilla back to the 
cardo. The base of the lingual fundament is at da. in Figure 30 (Plate 
5), and that of the maxilla at ba.!; consequently the stalk is developed 
in a superficial groove of the germ band itself — that part of the germ 
band connecting the base of the lingua with the extreme base of the 
maxilla, In ventral aspect at Stage 7 (Plate 5, Figure 29, pd.’), the 
continuity of the stalk along the surface of the maxillary pocket is evi- 
dent. Dorsal to the stalk, of course, the base of the maxilla is connected 
with the head, but under the connecting region passes the stalk. 
I must now explain how maxillary muscles become attached to the 
stalk in spite of the fact that the latter is a superficial formation of the 
hypodermis. This may be learned from transections at Stages 7 and 8, 
but also, and more easily, from good serial sections of an adult head, 
