364. EXTERNAL ANATOMY OF INSECTS. 



and become a kind of accessory Labium, Maxilla, SfC. 

 TJius in the Myriapods, the anterior pair of legs assume 

 a Maxillary farm and office a ; the Presternum those of a 

 Labium b : in the Arachnida, also, the anterior Coxae are 

 accessory Maxillae. In this Class, likewise, as has been 

 more than once observed c , the representatives of the inte- 

 rior pair of Antennae of the Crustacea, are thought 

 to assume the form and the functions of suctorious Man- 

 dibles d . 



ii. Facies (the Face). The upper surface of the head e . 

 It includes all the parts that lie between its junction 

 with the Prothorax and the Labrum: viz. Nasus, 

 Postnasus, From, Vertex, Occiput, Gence, Tempora, 

 Ocidi, Siemmata, and Antenna?. 



1 . Nasus (the Nose). That portion of the face, often 



elevated and remarkable, situated between the La- 

 brum, Postnasus, and Gence, and with which the 

 Labrum articulates; called by Fabricius the Cly- 

 peus f . It includes the Rhinarium. 

 A Rhinarium (the Nostril-piece). The space between 

 the anterior margin of the Nasus and the Labrum, 

 in which, in vertebrate animals, the nostrils are often 

 situated g . — N. B. This is remarkable in some La- 

 mellicorn beetles, as Anoplognathus Leach. In Ne- 

 crophorus, and some others, it is membranous. 



2. Postnasus (the Postnasus). That part of the Face 



immediately contiguous to the Antenna, that lies 



a Plate VII. Fig. 11, 13./'. " Ibid. Fig. 11. d'. 



c See above, p. 18, &c. f ' Plate VI. Fig. 10. c'. 



e Plate VI. Fig. 1, 4, 10. a. * Ibid. a. 

 * Ibid. s'. 



