HEMIPTERA. 199 



somewhat oval behind. The rostrum is long, slender, and four- 

 jointed. The wing-covers are longer than the abdomen, or are very 

 short. In the long-winged forms the membrane is usually furnished 

 with four long veins bounding three discal cells, which are often 

 open. From these cells diverge veins all around and form several 

 marginal cells. (Fig. 168.) 



Only three genera occur in our fauna; these can be separated by 

 the following table :* 



A. Pre-acetabula remote from each other. Clavus and corium semi-transparent. 

 (Sub-family Coriscinae.) i. CORISCUS. 



AA. Pre-acetabula close together. Clavus and corium opaque. (Sub-family 

 Nabinae.) 

 B. Joint 2 of rostrum longer than joint 3 ; joint 2 reaching base of head. 



2. PAGASA. 



BB. Joint 2 of rostrum shorter than joint 3 ; joint 2 not reaching base of 

 head. 3. NABIS. 



Corlsc us ferns is one of our most common species. This insect 

 measures about 8 mm. (0.3 in.) in length. It is pale yellow with nu- 

 merous minute brown dots. The veins of the mem- 

 brane are also brownish. This species is widely dis- 

 tributed both in this country and in Europe. It 

 secretes itself in the flowers or among the foliage 

 of various herbaceous plants, and captures small 

 insects upon which it feeds. Fig. 168 represents the /JrJ* "*** 

 wing-cover of this species. 



Corlscus subcolcoptrdtus is another very common species, and one 

 that is quite likely to attract attention. Although I have collected 

 very many specimens of it, I have met with only the short-winded 

 form. This is of a shining, jet-black color, with the edge of tin 

 abdomen and the legs yellowish. The specimens before me have 

 short wing-covers which barely extend to the second abdominal 

 ment. Uhl< that the long-winged form is much narr< 



behind, and the wing-covers and abdomen are rather dusky, or pice- 

 ous, than black. 



Family X XI V. PlIYMA riD/H.f 



rhywti: -i more poorly ! in this country 



than the preceding family; but. as m that case, some of tlit 



* Prrp.rr .! by Professor H. E. Summers. 



. maiidse, Phymala: fkyma (Qvfjta), a tumor. 



