1NSECTA. 



885 



TABLE OF THE PARTS AND APPENDAGES OF THE HEAD. 



Fifed parts of the head external xin Jiu-i . 

 (a) occiput, including the foramen occipitale and base <>/' the skull, and forming part of 



4, epicranium vertex, Kirby epicritne, Straus. 



(b 1) ocelli stemmata. 



c, oculi corners, Strata. 



d, clypeus anterior . . . . ) nasus, Kirby chaperon, Straw. 



</,*clypeus posterior.... ji clypeus, Fabriciia 



, gula, Kirby piece basilaire, Strata. 



c, labrum 

 j, mandibulx 



Moveable parts of the head. 



maxillae, 

 into . . , 



j"l, cardo, Kirby branche transrersale, Strata, insertio, Newman 



I 2, stipes, Kirby piece dorsale, Straus; maxilla, Newman 



I 3, palpifer, Newman . .squame palpifer, Straus, bears 

 divided I 4, the maxillary palpus, A. 

 j 5, laeinia, Mnchin/, Newman; inlermaxillaire, Straw, divided into 



6, galea, Fabricius ; lobus superior, Kirby. 



7, lobus inferior, Kirby. 

 \_ 8, unguis, Kirby. 



ligula, Newman; labium, Macleay. 



f t, ligula, Newman ; I 

 ,', labium.. U, the labial palni. 



j /, mentum, Macleay; 

 \.m, submentum . . .. st 



labium, Newman \ piece prebasi- 



r stipes, Macleay ; insertio, Newman ) laire, Straus. 



12, lingua, Newman. . . .hypopharynx, Savigny. 



A, antenna: 



f scapus. 

 ? pedicella. 

 (. clavola. 



Kirby. 



Sub-segments of the head. 

 1st includes labrum and labium. 



2d includes clypeus anterior and mentum .... 

 3d includes clypeus posterior and submentura 

 4th, obsolete, orbits and bones of the antenna: 



5th includes epicranium and gula 



The above table exhibits the whole of the 

 p:irts yet found in the cranium in the most 

 prit.ct order of Insects, the (Wen/''' 1 ' 1 ''; but it 

 must be remembered that many of these parts 

 are less perfectly developed in the other Orders, 

 and in some of the species have not yet been 

 discovered. 



Commencing our examination of the head 



at the posterior part of its upper surface, we 



observe that the occiput ( n, Jit:. HiiOJ is that 



portion of its base which is articulated with 



the anterior margins of the prothonix. It is 



perforated by a large foramen, through which 



the organs of the head are connected with 



"f the body. It is very distinct in the 



II Nitrous and most Coleoptera, and in some, 



the Stapliytinitlu', Ctmiliiilir, and Silphidf, is 



onstricted, and extended backwards so as to 



Min a complete neck; but in others, as in the 



urcu/ionia<r, it is short and hardly distin- 



lishable from the epicranium (6), of which it 



i - the continuation and posterior boundary. 



Interior of the head. 



^ os epipharyngeum, 

 ' ( os hypopharyngeum anterius. 

 os hypopharyngeum posterius, x. 



$ laminae orbitales, w ; and ossicula antenna- 

 ' ) rum or toruli, r. 



Ssutura epicranii, p. 

 os transversum, z. 

 laminae squamosx, s and v ; lames laterales, 

 Straus. 

 tentorium, Burmeister, u ; arcade, Straus. 



The epicranium is the whole of the posterior 

 and upper surface of the head, bounded pos- 

 teriorly by the occiput, laterally by the cornea 

 and sides of the gula, and anteriorly by a tri- 

 angular suture which extends from the anterior 

 margin of the cornea; to the middle of the 

 head between the eyes, where its apex unites 

 with a longitudinal suture which extends along 

 the median line to the occiput. Tins trian- 

 gular suture is a marked character in the head 

 of many insects, both in the, larva and perfect 

 state, and is of great importance in deter- 

 mining the number of the sub-segments. It is 

 very distinct in the larvae of Lepidoptera, and 

 is as marked in the McluluiithU/te and the 

 fitiip/ii/liniiltr as in the Hydraus. In some of 

 the beetles it is indistinctly marked on the 

 upper surface, but forms elevated ridges on the 

 interior surface. This is particularly the case 

 in the Hydrous. In the Dyticus it is more 

 distinctly marked by a lighter colour of ttie 

 skull, while in the common dung-beetles, Get- 



