264 



Hominoxious Arthropods 



j. No ventral plate or shield in either sex (fig. 153). R. 



bicomis from the United States Rhipicentor Nuttall 



jj. Males with a pair of adanal shields, and usually a pair of 

 accessory adanal shields. Numerous species, among 

 them R. sanguineus (fig. 154) and texanus, the latter 



from the United States Rhipicephalus Koch 



hh. Anal grooves faint or obsolete; no marginal festoons. 



i. Short palpi; highly chitinized; unfed adults of large size; 

 coxae conical; male with a median plate prolonged in two 

 long spines projecting caudad; segments of leg pair IV 



greatly swollen (fig. 155, 156). M. lointhemi 



Mar gar opus Karsch 



152. 



Monieziella (Histiogaster) erntomophaga-spermatica, ventral aspect, 

 male and female. After Trouessart, 



ii. Very short palpi, ridged dorsally and laterally; slightly 

 chitinized; unfed adults of smaller size; coxae I bifid; 

 male with adanal and accessory adanal shields (fig. 139). 



B. annulatus Boophilus Curtis 



ff. Palpi longer than broad (fig. 157). 



g. Male with pair of adanal shields, and two posterior abdominal 

 protrusions capped by chitinized points; festoons present or 

 absent. Several species, among them H. aegypticum (fig. 140) 



from the old world Hyalomma Koch 



gg. Male without adanal shields but small ventral plaques are 



occassionally present close to the festoons. Many species, a 



few from the Unted States (fig. 157) . . . . Amblyomma Koch 



h. Coxa I with but one spine; metatarsi (except I) with two 



thickened spurs at tips A . maculatum 



hh. Coxa I with two spines; metatarsi without stout spurs at 

 tips, only slender hairs. 



