DESCKIPTION OF PARTS. 9 



qiicntly dentate or toothed, the teeth being arranged so as to .sliiil witliin each (jlher. Below 

 the upper jaw arc the feeler jaws, or niaxill.T ; tliese also move horizontally : they are 

 8maller,and, insleml of notches, their inner edges are furnished with hri^tlesor haii-s ; they 

 are articulated to the throjit by a hinge (cardo), which places tlicni at right angUs to the 

 stipe or stalk, which last is pretty tliick and strong at its upper i)art. Attached to this is 

 the feeler-ljearer, so called beciiuse the niiixillary palpus is inserted on its outer edge. The 

 terminal portion of (he maxilla is the maxillary lobe, which is freijuently toothtd at its 

 extremity. The maxillary palpus is a filiform, jointed process, which always dis'inguiihes 

 the maxilhv from the mandibles. The proportion of joints is variable, and in number they 

 never exceed six. The terminal joint is quite variable in form in the different giiiera, and 

 hence becomes an important characteristic. The under lip is called a /oLium ; it antagonizes 

 the labrum : at its base is the mcntum or chin. The anterior part bears tlie labial palpi : 

 the terminal portion is the ligufa, and is often lobed. The labial palpi are jointed, l)ut the 

 joints never exceed four. The tongue, in the Carabida-, is a lining membrane of the under 

 lip, which protrudes ahiug its anterior angles, or in front : it is obscure among the Colco- 

 ptera,but more distinct among the Orthoptera. The mouth designed forsuctfon is not vcrj- 

 dissimilar to the one formed for mastication. The mandibles have undergone nitdificatitcs 

 which are rel'erred to tliree types, that have received the ftdlowing appellations : jrciuvscis, 

 proboscis, and haustillum. The tube is formed by the elongation of the maxilla and accessory 

 parts : so also it is formed by the mandibles. 



The thorax is the section of the insect which lies between the head and aldinicn : it 

 supports the legs. Three principal pieces enter into its composition : the anterior supports 

 the fore-legs, and is called the prot/iorax; the next, the mesothorax, which supports the 

 middle legs and fore-wings ; the last, the vietathorax., which supports the hiud-legs and 

 hind-wings. The inferior part of the thorax is covered by a plate, called the prostemvm by 

 Bi iiMEisTKtt. The sculcllum is a triangular piece of integument interposed between the 

 elytra at their base : sometimes it is concealed by the elytra. Ctmnected with the scutellum 

 is the/rc7i«/n, a membrane designed to regulate the quantity of movement belonging to the 

 elytra : in the Fulgura it consists of cartilaginous elastic rings, which admit of tension and 

 relaxation. The mesotliorax has another important division, called \hc scttpu/a- : they assist 

 in forming the articulating socket of the elytra ; they pass down the sides of the second 

 thoracic segment. The mesothorax has also its spiracle : on the under side of this segment 

 is placed the mesostemum ; it contains the sockets of the middle legs. The uiclathorax is 

 the posterior segment of the thorax, which supports the hind-legs and the inferior wings : 

 it is well developed in the Coleoptera and Orthoptera. The best authorities regard it as 

 admitting of a division into seven pieces : the dorsal portion is the vieltncfuvi ; it is 

 quadr.uigular, and notched in front. The nietathorax is separated from the abdomen by a 

 parietal wall called the mctnphrogma, and from the mesothorax by the vusi jhrcgma. The 

 lateral portions of (he metathoiax are provided with horn) plates, ternud by Kipb^ and 



[ AGRIcaLTURAL REPORT — VoL. V.] 2 



