146 INSECTS. 



Those which we shall notice are the species of A'phis, 

 commonly known as Plant-lice and Green-fly, which 

 are found too frequently upon unhealthy plants. The 

 species figured (PL X. fig. 2) is that of the geranium 

 (Pelargonium). The head is small and notched or 

 emarginate. The body is oval and furnished behind 

 with two prolonged tubercles, these being covered 

 with scales, giving them a somewhat striated appear- 

 ance (fig. 2b). The antennae are 6-jointed (c), the 

 second joint being very small, the last joint long, ex- 

 cavated on one side, and ringed : these organs are 

 reflexed over the body in the natural state. There 

 are two compound eyes, and three simple eyes or 

 ocelli, forming a triangle on the top of the head. 

 The proboscis or rostrum is bent under the body, 

 4-jointed, and contains three setse, two of them form- 

 ing very slender lancets. The legs are long; the 

 tarsi (fig. 2 a) 2-jointed, the first or basal joint being 

 very minute, and the last furnished with two claws. 



In a colony of these insects, some are winged and 

 some wingless; those without wings being usually 

 in the larva state, the pupse having rudimentary 

 wings, and the males and females usually perfect 

 wings. Aphis brass'icae is the destructive turnip-fly. 



COLEOP'TERA (/coXep?, sheath) . This, which is the 

 last Order to be noticed, contains the Beetles, so 

 easily recognized by their hard and horny fore wings 

 or wing-cases. The parts of the mouth in these 

 insects are exceedingly well adapted for examination ; 

 and as they are not fused or consolidated with each 

 other, they serve to illustrate the typical constitution 

 of the organs as existing in these animals. 



Pteros'tichus (Ster'opus) mad'idus (PL X. fig. 23) is 

 common in cellars and garde as among vegetable rub- 

 bish. The body of this beetle is shining black, the 

 head projecting; the antennae (fig. 23 a) are filiform, 

 and compressed towards the end. The thorax is some- 

 what rounded, with a deep rough pit and a longi- 



