INVERTEBRATE ZOOLOGY. 39 



Order G. Rhynchota (Hemiptera).. Mouth parts modified to form a straight 



jointed beak, which lies between the 

 coxal joints of the legs. Wings either 

 membraneous and alike, or with the 

 outer diagonal half of the upper wings 

 pergamenteous. Many forms wingless. 

 Hemimetabolic. ic Coreiis, Cicada. 



Order 7. Lepidoptera Mouth parts a double coiled proboscis, 



formed by the first maxillae. Wings 

 alike in texture, membraneous, covered 

 with minute colored scales. Holometa- 

 bolic. if Papilio. Sphinx. 



Order 8. Diptera Mouth parts variously modified, sucking. 



piercing or lapping — never Inting. Fore 

 wings membraneous, liind wings reduced 

 to minute knobs — the so-called balancers. 

 Holometabolic. 

 •^ Culex, Musca. 



Order !). HyuK'uoptera Mouth parts biting— or biting and lap- 

 ping. Wings membraneous, alike in text- 

 ure, but hind pair rediTced in size. Body 

 generally much constricted between tho- 

 rax and abdomen. Ovipositor of male 

 generally accompanied by organs for 

 sawing, boring or digging, and in some a 

 venomous sting. Holometabolic. 

 if Vesjxi. Fonnica. 



Cladus II. MoUusca. 



Class I. Amphineura A small group of bilaterally symmetrical 



marine molluscs with very primitive 

 characteristics. Thej' have a nerve ring 

 around the mouth, from which pass two 

 lateral and two ventral nerve cords con- 

 nected by transverse commissTires. 



