PRIONUS CALIFORNICUS MOTSCH. 

 Rensselaer J. Smith, M. D., Milpitas, Cal. 



The family of our illustration is a very large and beautiful one, the 

 Cerambycidae (Long-horned beetles). Sub-family Prioninae. Species Prionus 

 Californicus Motsch. Natural size, cut original. Taken at electric light 

 July, 1913. 



External anatomy Coleoptera or Beetles: 



For simplicity divide into three regions; the head, thorax and abdomen. 



The heads of beetles vary greatly in shape and size. The head is joined 

 to the thorax by a membrane and is more or less constricted into a neck. The 

 mouth, eyes and antennae are parts of the head. Examine the eyes of several 

 beetles with a microscope and you will find that they vary greatly in size and 

 shape. They may be called compound eyes as they are made up of many 

 single lenses, some coarsely and others finely granulated. The lateral, movable, 

 jointed appendages of the head are known as the antennae. Huxley states that 

 they are the seat of smell. The number of joints vary from two to twenty-seven, 

 ordinarily eleven. Mouth parts: upper lip labrum (la' brum) ; under lip labium 

 (la' bi um) ; upper jaw mandibles (man' di bles) ; lower jaw maxillae 

 (max il' lae). 



Thorax or second part of body to which are attached the legs and wings: 

 it is divided into three parts and starting from the head these are called pro- 

 thorax, mesothorax and metathorax. 



The leg: next to the body in the cut the visible part is the femur or 

 thigh, next the tibia or shank, and the last part is the tarsus or foot which has 

 segments, the last segment has two claws. 



The wing-covers are called elytra (el' y tra), singular elytron. In different 

 species these vary greatly in shape, sculpture, color and decoration. 



America north of Mexico has nearly 12,000 species of beetles representing 

 about 80 families. 



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