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divided in the median line; each lateral part has in front 

 an articulation to which the hooks are connected, one on 

 each part (Fig. 13): the two lateral parts of the skeleton 

 are mutually connected by an arched, transverse rod which 

 is placed on the spot where the plate present in the first 

 stage was placed. Most species are amphipneustic, but 

 some (Panzeria rudis and Ocyptera brassicaria) are meta- 

 pneustic. The anterior spiracles are elongated and generally 

 divided into two knobs (Fig. 14) which may sometimes 

 (Viviania cinerea Fig. 37) be very small. The larva of 

 Cnrcelia gnava has in this stage a larger number of knobs 

 on the anterior spiracles (Fig. 29). The posterior spiracles 

 resemble those in the first stage, thus having only two 

 knobs, but the knobs are somewhat larger, sometimes sinuous 

 (Ocyptera brassicaria Fig. 42), and sometimes partly con- 

 fluent (Steiniella callicln Fig. 26). 



Third stage. The anterior part of the pharyngeal 

 skeleton is connected with the posterior part by an articu- 

 lation (Fig. 16). All larvæ. except those of Octjptera brassi- 

 caria, are amphipneustic. The anterior spiracles are large 

 and generally richly branched (Fig. 22). The posterior 

 spiracles are surrounded by a chitinous border generally 

 dividing the spiracle into areas (Fig. 49). Each spiracle 

 has three respiratory areas at least. 



In the larvæ examined the armature of spines is present 

 on the front and hind margins of the segments. The spines 

 on the front margins are largest on the anterior segments 

 and decrease in size behind. The spines on the hind 

 margins are generally not found on the anterior segments, 

 but appear on the third or fourth segment and increase in 

 size behind. All the spines on the front margins point 

 backwards, and all those on the hind margins point for- 

 wards (Fig. 48). The last segment has a girdle of spines 

 directed forwards. In the first stage some single, very large 



