1, Bd) are very intimately fused together to form what is called the "lower lip" or labium, a firm transverse plate representing the fused basal portions of the maxillae, which may carry a small median "ligula," representing apparently the fused inner maxillary lobes, a pair of paraglossae (outer maxillary lobes), and a pair of palps.
The inner lobe (lacinia) of the first maxilla terminates in an articulated hook, while in the second maxillae (labium) both inner and outer lobes ("ligula" and "para-glossae") are much Gyrinus sulcatus reduced.
In specialized biting insects, such as beetles (Coleo C ptera), the labium tends to become a hard transverse plate bearing the pair of palps, a median structure - known as the ligula - formed of the conjoined laciniae, and a pair of small rounded processes - the reduced galeae - often called the " paraglossae," a term better avoided since it has been applied also to the maxillulae of Aptera, entirety different structures.
- Diagram of a transverse section through the body-wall of a young Ligula, illustrating the microscopic structure of tapeworms. a.
Ligula, unsegmented externally, occurs in birds.
E, First maxilla; a, cardo; b, stipes; c, galea; d, lacinia; e, palp. B, Second maxillae (Labium); a, mentum; b, ligula (between the two galeae); c, c, palps.
A, mandible; b, c, palp and lacinia of first maxilla; d, e, g, h, mentum, palp, fused laciniae (ligula or "tongue") and galea of 2nd maxillae.
Structurally the Neuroptera are distinguished by elongate feelers, a large, free prothorax, a labium with the inner lobes of the second maxillae fused together to form a median ligula, membranous, net-veined wings without hairy covering, those of the two pairs being usually alike, the absence of abdominal cerci, and the presence of six or eight Malpighian tubes.
Mxp, Maxillary palp. 1, Ligula or "tongue."