PEELIMINAEY CLASSIFICATION OF SCOLYTOIDEA. 



183 



(Part I, figs. 23, 31, and 33) and to the anterior margin of the pro- 

 notum and the posterior dorsal area of the head. 



Internal Anatomy. 



Considerable study has been made by Lindemann, Ntisslin, Fuchs, 

 and others, of certain elements of the internal anatomy, especially 

 the proventriculus of the digestive system and the male and female 

 reproductive organs. It is evident, however, from a review of the 



v^ 



'^"^^ 



] 



it 



- 



.,.f 



^ 



k-V 



Fig. 98.— Proventric- 

 ular plate of Ips 

 emarginatus, inner 

 aspect: a, Entire 

 plate; 6, divided an- 

 terior plate; c, poste- 

 rior or masticatory 

 plate; d, median 

 longitudinal suture; 

 e, sutural teeth; /, 

 median transverse 

 sutm'c; g, transverse 

 or apical teeth of an- 

 terior plate; ft, lat- 

 eral margin or mar- 

 ginal suture; i, lat- 

 eral or masticatory 

 teeth; ia, closing 

 bristles or teeth; ,;, 

 femora of the mas- 

 ticatory teeth; k, 

 femoral teeth or 

 ridge; I, mastica- 

 tory brush; m, mar- 

 ginal bristles or 

 fringe. (Original.) 



Fig. 99.— Proventricular 

 plate of Scolytus scolytus: 

 b, Divided anterior plate; 

 d, median suture; ft , lateral 

 margin; gl, apical lami- 

 nate teeth of posterior 

 plate. (Original.) 



results, that as a sufficient basis for 

 general or specific conclusions a far 

 more compreh,ensive study is necessary. 



DIGESTIVE SYSTEM. 



Fig. 100. — Masti- 

 catory plate of 

 Crossotarsus le- 

 contei; c, Masti- 

 catory plate; la, 

 apex and lateral 

 serrations o f 

 masticatory 

 teeth. This fig- 

 ure should be 

 viewed in a re- 

 versed position 

 in order to rec- 

 ognize the ele- 

 vated character 

 of the median 

 longitudinal 

 area. (Original.) 



Tlie general type of the digestive sys- 

 tem is shown in Part I, figures 35 and 36, for the 

 adult and figure 43 for the larva. Lindemann (1876, pp. 148-169), 

 Niisslin (1912, pp. 85-87, figs. 135-143), and Sedlaczek (1902, pp. 

 241-263, figs. 1-20) show that there is a wide variation in some of 

 the elements and especially in the proventriculus and the median 

 and posterior section of the midintestine, but to what extent these 

 variations are of value in taxonomy has not been determined. 



Proventriculus. 



The proventriculus (figs. 98-100; Part I, figs. 35-38) is of special 

 interest, and the work of Lindemann, Fuchs, Niisslin, and others 

 has contributed much valuable information on the structural ele- 

 ments. 



