56 PARTIAL ORISMOLOGY. 



and relation to the other organs of the mouth ; there are, however, no 

 differences exclusively peculiar to it, and we may consequently refer to 

 General Orismology for the notification of its discrepancies, without the 

 necessity of repeating them here. 



In explaining the construction of the upper jaws (mandibulce, PL IV. 

 f. 8), Kirby and Spence have, and we think very happily, instituted 

 a comparison with those of the superior animals. They consequently 

 distinguish the PROSTHECA (prostheca] in the mandibles, which is a 

 cartilaginous process, near the base within, and is found very generally 

 among the Brachyptera ; for example, in Staphylinus incucillosus. 

 They call TEETH {denies) the pointed processes on the inner side, 

 and very skilfully distinguish the superior, compressed, sharp edge as 

 CUTTING TEETH (denies incisivi, the same figure, a) ; or they call 

 them CANINE TEETH (denies laniarii, s. can in i), when they are very- 

 sharp and conical. GRINDING TEETH (denies molares') are the inferior 

 thicker teeth, provided with a broad grinding surface (Melolonthd). 

 The MOLA, or grinding surface (mola, the same tig. b), they call the 

 broad, flat, and often, like the teeth of the elephant, ridged space of the 

 molares of many insects (for example, of the Bombi, Melolontha, &c.). 

 In the Coleoptera, this molar tooth is clothed laterally with short stiff 

 hair, which Straus calls the BRUSH (brosse). The processes at the 

 base are also important, from their supplying the articulation of the 

 mandible with the head ; they are three in number, and are placed at 

 the ends of the edges, beneath which the three surfaces of the mandibles 

 join. The lower one, viewing the mandible in its natural position, is 

 shaped like a ball, and corresponds with a cavity, or socket, in the 

 head. The upper one, on the contrary, is concave, and consequently 

 forms a socket corresponding with the ball upon the head-case (the 

 same fig. d). The third is less observable, and lies within towards the 

 orifice of the mouth, at the end of the masticating edge of the mandible 

 (the same fig. e). The muse, adductor mandibulce is attached to it ; 

 its antagonist, the muse, abductor, is inserted in the exterior margin, 

 between the two articulating processes. The upper jaws very gene- 

 rally consist of a firm corneous substance (mandib. corneas) ; in other 

 instances they are membranaceous (m. membranacete), as in the Lamelli- 

 cornia coprophaga: in these also they have in general a hooked shape. 

 In the Hemiptera, and many Dlptera, they are SETACEOUS (m. setacece, 

 xetce rostri) ; but in other families of the latter order (Tabanica) they 

 are LANCEOLATE (m. lanceolatce). 



Very similar forms are observable in the under jaws (maxillae}. The 



