THE HEAD. 61 



the upper and under jaw. Between them is found the orifice of the 

 mouth, at the apex of a small lanceolate tongue, concealed within the 

 sheath (fig. 10, e, and fig. 13, e}, which is enclosed by the setae of the 

 jaws. The jointed sheath of the promuscis is called vagina; the setae 

 of the jaws, setce super lores et inferior es ; the central tongue, ligula. 



The SPIRAL TONGUE (lingua spiraUs, Fab. ; antlia, Kirby and 

 Spence: spiritrompe, Lat.), or sucker of the Lepidoptera, is the 

 third form of a suctorial mouth. It equally consists of all the organs 

 of a masticating apparatus, which, however, here, adopt the following 

 configuration. A small triangular piece, attached to the clypeus, and 

 which extends downwards towards the mouth, is the LABRUM (fig. 15, 

 a, and fig. 16); near to it are placed the short, conical, slightly-bent 

 MANDIBLES (fig. 15, b, l>, and fig. 17)- They are both covered by the 

 large forward ly-bent labial palpi (PL VI. f. 3, d), and can be dis- 

 covered only by a very laborious research. The MAXILLAE have the 

 same form they are described to take above in the masticating appa- 

 ratus ; but the superior lobe is stretched into a long, cylindrical, 

 transversely-wrinkled filament (PI. VI. f. 1,); at the inner margin 

 of which, two narrow bands are found (fig. 2, a, a), which symme- 

 trically agree with those of the other maxilla, and by means of which, 

 therefore, the space occurring between the two maxillae is formed into 

 a tube (fig. 2, o). The filiform maxillae are also hollow (fig. 2, p, p), 

 and by these cavities they are connected with the furcate commence- 

 ment of the eesophagus, so that the Lepidoptera have, as it were, two 

 mouths, or rather two separated suctorial tubes. Where the upper 

 filament of the maxilla is attached to the stalk, a small two-jointed 

 FEELER (fig. 1, b} is inserted. The LABIUM (PI. V. f.18, e, and PI. VI, 

 f. 4, e}, is tolerably large, generally triangular, and frequently divided 

 at its apex. Each lobe bears a large, three -jointed, very hairy 

 FEELEK (PI. V. f. 18, d, d, PI. VI. f. 3 and 4, d, d), which falls 

 forward, and forms the sheath of the sucker, when it is drawn up 

 spirally in repose. 



The suctorial organ of the bees (PI. VI. f. 2 9, see description of 

 the plates), and of the other suctorial Hymenoptera, is but a more or 

 less prolonged transformation of the masticating apparatus, the same 

 as that of the May flies (Phryganeodea), and we shall therefore treat 

 of them in detail in our systematic description of their families. The 

 mouth of the flea (Puhx), to which Kirby and Spence ascribe a 

 peculiar suctorial organ, does not essentially differ from the structure of 

 those of the Diptera, which have no fleshy lip ; and which we shall also 



