GENEHA OF HYMKNOPTERA. 



Tlu- Hi:a[) (liii-. 1. t'riiiit vii-w) is <.'*'iu'rally transvei'se and nar- 

 rower, ranly wider, than tlie thorax, and varies greatly in form, 

 being .sonietirncs globoi?e, (|uadrate or elongate, witli all the gradations 

 from nne t<> the other; it i> frecjuently more or less ext^'nded behind 

 the eyes; the vertex or erown is the highest part, on wliicli the sim- 

 ple eyes or oeelli (e) are j)laeed. back of it is the oeeipiit ; anterior to 

 the oeelli is the front or face upon which the anteniuc are inserted, 

 while back of the eyes are the cheeks which are sometimes more or 

 le.<s inflated, and very raicly dentate. Ihe cijeK (a) are generally 

 large and lateral, naked, rarely pilose, occasionally occupying in the 

 males of certain groups, the greatest portion of the head ; thev varv 

 nujch in form and size, being sometimes reniform, ovate or circular, 

 sometimes small or even minute and very rarely wanting; they are 

 acc(»mj)anied by three small simple oceUi (e) placed either in a tri- 

 angle or in a .straight or curved line upon the vertex, but in the 

 apterous females of certain genera of Heterogyna and .Mutillidje 



these ocelli are entirely wanting, while in 

 some of the Lai-rida3 and Sapygidae, the pos- 

 terior pair is distorted and subnljsulete ; oc- 

 casionally, as in Ophioii, they are unusuallv 

 large and prominent. The c/i/jf/'K.^ (b) is 

 placed on the front, beneath the in.sertion of 

 the antennae (f) and is variously formed, 

 usually shield-like, but often narrow and 

 transverse, and sometimes produced into va- 

 {.'ij,. 1. rious cui-ions sliapes, the apical margin being 



a, eycs;b, ciypeusic, lab- often denticulate; in the Dorylidie it is very 

 rum: d. nKindiiiies; e, ocelli; niiuute or obsolete. T\w mandible.^ or jaws 



f, insertion of .intcnnae. , . , , , ' 



(d ) are inserted beneath the eyes and on each 

 side of the iiKiiitii opening, rarely contiguous at their base; they 

 vary much in fiirni and size, and are simple ov nioi'e or le.ss dentate 

 on their inner margin and apex, .sometimes they are long and sickU- 

 shaped. The I'lhriiiii, or roof of the mouth (c), is variouslv shaped, 

 transverse, ovate, cuneiform, or rostriform, and is situate in front of 

 the clypeiis ami between the mandibles, and is often concealed by 

 them. The inner parts of the mouth, which reach the fullest de- 

 velopment in the Bees, are, in short, com]iosed of a jiair of lou"- 

 membranous or eoriaeeous maxilhe, each pruvidecl witii a |ialpus 

 varying in the mnuber of joints from l-(i, ami a lower lip or toiiirue, 

 having a l)a.sd meiitum fi-uMi which proceeds the hihiiim and its 



