THE THORAX. 105 



PALMATE (palmata, PI. XVI. f. 2), when the whole shin is com- 

 pressed, and upon its exterior margin there are short but strong teetli 

 (Hister, Ateuchus). 



FOLIACEOUS (foliacea, PI. XVI. f. 11), when, instead of its usual 

 tubular form, the shin is entirely or partially extended into a thin 

 horny plate (Lygceus, Coreus) ; or CLYPEATE (clypeata, PI XVI. 

 f. 12), when the enlargement is only upon one side, and is slightly 

 convex (the males of some Crabro's). 



SCOPATK (scopacea, PI. XVI. f. 13), is a broad shin, densely covered 

 with short hair (many bees). This, considered as a distinct organ, 

 Kirby and Spence call a brush (sarothrum). 



5. FOOT. Of all the divisions of the leg, the joints of the feet are 

 subjected to the greatest varieties of form. Most frequently cylindrical, 

 by the narrowing of the base they gradually pass into the conical shape, 

 but even these feet are somewhat flattened beneath, and thus form a kind 

 of sole (for example in Ca.ra.bus). This kind of narrow sole has no 

 other distinction than that it is limited by two small ridges, which in 

 front are produced into two small spines (PI. XVI. f. 14). These 

 kind of feet are peculiar to those insects which run upon rough and 

 especially horizontal surfaces (the Carabidea) ; others, which move 

 upon perpendicular and moving objects, have flat broad joints, which 

 are provided with a peculiar clasping apparatus, Such flattened joints 

 are sometimes, cordate (PI. XVI. f. 15), triangular (f. 16), quadrate 

 (f. 17), simple, or emarginate in front (f. 15), sometimes more deeply 

 divided and bilobate (PI. XVI. f. 18). This last form is in the 

 majority of cases peculiar to the penultimate joint only (for example 

 in the Cerambycina, as Callidium violaceum) ; in other cases several 

 are divided, for example, the three first in Brachycerus, the third and 

 fourth in Lycus, &c. The individual joints are nearly 'equally long 

 and broad, but it is not unusual for the first to be longer than the 

 following, and it is then called, particularly when in its general 

 structure it diverges from" the following (as in the bees), metatarsus. 

 The remaining equal joints then form the TOE (digitus) or the FINGER 

 (dactylus) ; they are individually called the PHALANGES, and not, 

 as some writers presume, fingers and toes. All insects are conse- 

 quently one-toed (monodactyla), the genus X?/a. 111. (Tridactylus, 

 Latr.*) only having actually two equally long toes (PI. XVI. f. 19). 



* See Chaqientier, Hora Entomologies. Vrat. 1 825. 4to. p, 84 Tab. 



