TIIK HEAD. 49 



I. THE HEAD (Capvt). 

 66. 



The HEAD *, the first of the three divisions of the insect body, 

 displays considerable variety in its form. In general it approaches to 

 the globose, or semi-globose, and is surrounded by a plain corneous 

 case, and contains the different organs of the senses. From its sim- 

 plicity, it is evident that we cannot so readily distinguish by peculiar 

 terms particular divisions in it, as we can certain regions, and these 

 must agree with the analagous portions of the head of the higher 

 animals. 



With respect to the most usual forms of the head, modifications 

 of the globose seem to prevail, with the occasional predominance of 

 either its longitudinal or transverse diameter. Thence proceed the 

 egg-shaped, longitudinal, obtuse-triangular, heart-shaped forms, &c., 

 which we meet with in so many groups of insects. It is very fre- 

 quently produced into notches and prominences which are called HORNS 

 (cornua) ; these are always integral portions of the corneous case, and 

 are never articulated and moveable. 



67- 



The following are the portions of the head most usual to note. 



We must first distinguish the true SKULL (cranium, calva according 

 to others), and thence proceed to the generally moveable organs 

 attached to it ; it therefore comprises the whole of the head, excluding 

 the antennae, eyes, and oral apparatus. If we wish to notice the upper 

 part, from the front across the vertex to the posterior cavity, we call 

 it UPPER-HEAD, SKULL-CAP (calva, epicranium, Straust), PL HI- 

 f. 11, A. It is limited in front by the CLYPEUS (ch/peus), called LOWER 

 FACE (Jiypostoma, in the Diptera by Meigen and Bouche, the epistomis 

 of Latreille), or that portion which lies above the organs of the mouth ; 

 it is bordered laterally by the sides of the head, and extends as far as 



* 111 explanation of our occasionally differing from other writers in the nomenclature 

 of the parts of the insect body, we refer to what we have said at 9, II. and the note. 



j- Considerations Generales sur rAnatornie comparee des Animaux articules. Par 

 Here. Straus-Diirckheim. Paris, 1828. 4to. av. 10 fig. (p. 52, &c). 



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