390 INSECTA. 



I will divide this section into two tribes(l). The Insects 

 which compose the first or the Acanthopoda are remarkable 

 for their flattened and tolerably wide tibiae, armed anteriorly 

 with spines ; for their short quadriarticulated tarsi, the hooks 

 of which are of the usual size ; and for their depressed body. 

 The presternum is dilated. The antennse are a little longer 

 than the head, arcuated, and formed of eleven joints, the last 

 six constituting an almost cylindrical and slightly serrated 

 club ; the second is short and not dilated. 



This tribe is composed of the single genus 



Heterocerus, Bosc. Fab. 



These Insects are found in the sand or mud, along the borders of 

 rivulets, marshes, &c, issuing from their holes when disturbed by 

 the trampling of feet. The form of their tibiae enables them to turn 

 up the earth, and conceal themselves in it; their tarsi can be flexed 

 upon the tibise. There also reside their larvae, which were first 

 discovered by M. Miger. 



H. marginatus, Fab.; H. leevigatus, Id.; Panz., Faun. Insect., 



Germ., XXIII, 12. A small, blackish, and silky Insect, with 



little yellowish or reddish spots, varying in form and number, 



and sometimes even wanting on the elytra. 



M. Gyllenhal observes that the tarsi really consist of five 



joints, the first of which is small and oblique. See Insect. Suec. 



I, p. 138. 



The second tribe, or that of the Macrodactyla, com- 

 prises Clavicornes with simple, narrow tibise and long tarsi, 

 all one genus excepted (Geo?*issns) , well distinguished from 

 every other of the tribe, by its antennae of nine joints, of which 



(1) We might also divide the section in the following manner. 



I. Antenna composed of eleven joints. 



A. Antenna clavate and very short. 



a. Tibia: spinous; tarsi quadri-articulated. 



Heterocerus. 



b. Tibiae simple; five joints in the tarsi. 



POTAMOI-HILUS. DrTOPS. 



B. Antennae filiform or slightly enlarged near the end, as long as the head 

 and thorax. 



Elemis. 



II. Antennae nine or six joints. 



Macronichus. Georissus. 



