SEVENTEENTH ANNUAL REPOHT. 



393 



The form of the palpi is an important character in classifying ticks 

 in their respective genera. 



Fig. 62.— Outline ventral view of male Boophilus to show structures used in classification: anus; 

 clypei or anal shields; g.p., genital pore; legs I to IV; the names of the articles are written on the 

 leg II. Greatly enlarged. Original. 



II. Body. — The body (figs. 42-49) varies greatly in form, being dif- 



. ferent in color, outline, 



j^:- ^.'" ^ and structure, not only 

 in the difi'erent genera 

 and species, but also in 

 the two sexes of the same 

 species and in the differ- 

 ent stages of the same sex. 

 This extreme variety of 

 appearance has led some 

 observers to describe the 

 different members of one and the same spe- 

 cies as representatives of different species, 

 and accounts to a great extent for the con- 

 fusion in the classification. An individual 

 specimen, if alive, will even change color while it is being studied. 



Fig. 63.— Anus of Boo- 

 philus annulatus. 

 Greatly enlarged. 

 Original. 



Fig. 64.— Stigmen of female Boophi- 

 lus annulatus. Greatly enlarged. 

 Original. 



