ADEPHAGA AMPHIZOIDAE PELOBIIDAE 



207 



genera ; the Carabides are next in importance, with upwards of 

 2000 species, but are divided into a comparatively large number of 

 tribes, each of which averages a much smaller number of genera 

 than do the tribes of Harpalides ; Pseudomorphides includes only 

 about 100 species ; and Mormolycides consists of the single genus 

 Mormolycc with three species. 



Fam. 6. Amphizoidae. Antennae destitute of pubescence : 

 outer lobe of maxilla not jointed; metasternum with a short 

 transverse impressed line on the middle behind. Hind legs slender, 

 not formed for swimming. This family is limited to the genus 

 Ampliizoa ; the species of 

 which may be briefly de- 

 scribed as lowly organised 

 Carabidae that lead an 

 aquatic life. The geo- 

 graphical distribution is 

 highly remarkable, there 

 being but three species, two 

 of which live in Western 

 Itforth America, the third 

 in Eastern Tibet. The 

 habits of American Am- 

 phizoa are known ; they pass 

 a life of little activity in 

 very cold, rapid streams ; 



FIG. 93. Amphizoa lecontei. North America, 

 they do not SWllll, but A, Larva ; B, imago. 



cling to stones and timber. 



The larva was recently discovered in Utah by Messrs. Hubbard 

 and Schwarz : : it has the same habits as the perfect Insect, 

 and in general form resembles the larvae of the genus Cardbus ; 

 but it has no terminal tube to the body, the abdomen consisting 

 of eight segments and a pair of short terminal appendages ; the 

 spiracles are obsolete, with the exception of a pair placed near to 

 one another at the termination of the eighth abdominal segment. 

 As regards the mouth this larva is Carabid, as regards the 

 abdomen and stigmata Dytiscid of a primitive type. 



Fam. 7. Pelobiidae. Antennae destitute of pubescence : outer 

 lobe of maxilla jointed, metasternum with a short transverse 

 impressed line on the middle behind. Hind legs rather slender, 



1 P. ent. Soc. Washington, ii. 1892, p. 341. 



