HEMIPTERA. 199 



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

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



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

 Nabinse.) 

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



2. Pag as a. 



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



head. 3. Nabis. 



Coriscus ferus 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 wing-cover 



insects upon which it feeds. Fig. 168 represents the %>us° r ' scus 

 wing-cover of this species. 



Coriscus 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-winged 

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

 abdomen and the legs yellowish. The specimens before me have 

 short wing-covers which barely extend to the second abdominal seg- 

 ment. Uhler says that the long-winged form is much narrower 

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

 ous, than black. 



Family XXIV.— Piivma rnu . » 



The Phymatida is even more poorly represented in this country 

 than the preceding family; but, as in that case, some of the species 



* Prepared by Professor II E. Summers. 



f Phymatidae, Phymata: phyma (<J>vjxa), a tumor. 



