OF Tin: DNITED STATES. |n I 



the Carabica the nearest approach to the Hydradephaga, Kirby l_t < > i 1 1 ir so far as to assi rl 

 that " its cognate forms are all in that ti With this view I cannot agree. That it 



is a water type of Carabica, must be admitted from its habits; but when w find the cha- 

 racteristic difference in the position of the anterior legs, 1 Inch distinguishes the Carabica 

 from the water beetles, is so much exaggerated in ( Imophron as to produce a form of pres- 

 ternum not found in any otlier genus o Ci rabica, we must consider the integrity of the 

 type as fully preserved, and we must view he ics rablances between Omophron and the 

 water beetles as the result of analogy, attending habits of life, and not as displaying any 

 direct affinity. It may be said that neither in the form of the head, the structure of the 

 antennae, the position of the anterior feet, the shape of the posterior cos . nor in the 

 structure of the legs, docs Omophron make any approach to Haliplus or Hydroporus. 



The true osculant between the Carab ca and wate ■ I eetles will be found in Bome genua 

 allied to Nebria, as that group alone mi kes any approach to the latter tribe in the position 

 of the anterii r feet : Opisthius on the one side, i nd A mphizoa, \\ bich, as I have atti mpt< d 

 to demonstrate,* is a water beetle, with ambulatorial, instead of natatorial legs, make 

 perhaps the nearest osculation that has yet been found. 



The special characters of this group are: 



The prosternum i~ wide, prolonged and truncate at the extremity; it is closely applied 

 to the metasternum, so that the mesosternum is concealed: the anterior act tabula are 

 entire, and mi >re distant than usual from the posterior margin of the prosternum, and from 

 each other; the anterior tibiae have a small deep emargination internally near the tip; the 

 elytra have fourteen deep striae: the first joint only of the anterior tarsi of the mail 

 dilated; it is large, oblong and de - ly spongy beneath. The first four joints of the an- 

 tennae are glabrous, and the maxilli earded at base, as in the preceding group. The 

 paraglossae are connate with the ligula. 



There are six - of Omophron known tome withm the United States, viz.: <>. 



dentatum L c.{ \nn. Lye. 5, 200;) O. G Use Lee. ibid.; O. tesselatum Say, (Zecontei 

 Dej.;] O. americanura Dcj. (Sayi Kirby;) O. labia turn Oliv. S , Dej.;0. nitidum 

 Ann. Lyc. I, I 17. i 



• Pi 



