plex structure, and the nomenclature of its separate parts somewhat involved. On examining the figure of the lower lip of the domestic cricket, (Pl. VI. fig. 6) it will be observed that it is divided into three distinct parts by means of well defined lines. The basal portion, (a) by which the whole labial apparatus is attached to the head, Kirby regards as the mentum. The second division (d) he considers as more directly answering to what is strictly called the labium in other insects; and the terminal portion (e) is merely an additional articulation to it, divided into two, three, or more lobes. "At first you would imagine the terminal part of this organ to be the analogue of the tongue, or ligula F; as it is indeed generally regarded by modern Entomologists. It seems like the tongue of the Carabi L, Dytisci, &c. to be a distinct piece, which has below it both labium and mentum: but when you look within the mouth, you will find a linguiform organ, which evidently acts the part of a tongue, and therefore ought to have the name; and the piece just alluded to must either be regarded as the termination of the lip, or as an external accompaniment of the tongue, analogous, it may be, to the paraglossæ in bees."[1]
The labial palpi are variously described by authors as consisting of three or four articulations. The number of joints is certainly alike in all the species, and the discrepancy alluded to, has probably arisen from some observers having included the minute
- ↑ Introd. to Entom. III. 424.
