PRELIMINAKY CLASSIFICATION' OF SCOLYTOIDEA. 



185 



as-; 



In addition to the foregoing, tlie%\Titer, during the years from 1892 

 to 1912, has studied the male reproductive organs of 68 species, repre- 

 senting 43 genera. The total species studied by all authors, with- 

 out duplication, is 147, 

 representing 57 genera, /*.- -/- . /.-_ -^^ 



The reproductive or- 

 gans of the male repre- 

 sent four primary divi- 

 sions or elements :(1) The 

 posterior chitinized di- 

 vision (fig. 102), (2) the 

 posterior membranous 

 division(fig. 101),(3)the 

 median division, and ( 4) 

 the anterior division. 

 (See terminology, pp. 

 192-194.) 



POSTERIOR ELEMENTS. 



The posterior chiti- 

 nized elements ( divi- 

 sion 1) consist of four 

 primary sections, (a) the 

 body, (&) the end plates, 

 (c) the tegmen, and (<Z) 

 the spicule. In addition 

 to these more constant 

 elements there are (&1) 

 the seminal valve and 

 {1)2) the seminal rod, 

 both of which appear to 

 be more intimately asso- 

 ciated with element ?> 

 than with element a; also, 

 there are ( e) the connect- 

 ing membrane and (/) 

 the muscles. From a 

 somewhat comprehen- 

 sive study of the chiti- 

 nized elements in the 

 scolytoid beetles in com- 

 parison with those in 

 other insects it seems plain that, so far as these beetles are concerned, 

 the chitmized parts of the male reproductive organs represent ele- 

 ments of the nmth and tenth abdominal segments, either as direct 

 modifications of primitive sclerites or as independent developments 



Fig. 103. — 7ps cnarqinatus: Chitinous elements of male repro- 

 ductive organs. /, ventral aspect; //, dorsal aspect. See 

 terminology, Division 1, pp. 192-193. (Original.) 



