OF WASHINGTON. 235 



fRostrum long, palpi longer than broad family Ixodidae 



2. -l Rostrum short, palpi short, subtriangular, not, or only slightly 

 longer than broad family Rhipistomidae 



Family HAEMALASTORID^E. 



This family contains the cosmopolitan genus Haemalastor 

 Koch., and the European genus Sarconyssus Kolenati, the latter 

 found in caves in Austria. 



a. Last palpal joint longest and thickest genus Sarconyssus Kol. 



b. Third palpal joint longest and thickest genus Haemalastor C. K. 



Family IXODIDAE. 



f Body oblong oval, stigmal plate circular, peritreme round, stigma 



round, punctiform, maxillary armature extending down to the 



i. \ base of maxillae ; male without lamellae at posterior ventral 



area genus Ixodes Latr. 



[Stigmal plate reniform, peritreme comma shaped, stigma oval 2 



f Body nearly circular, male and female shield ornate, palpi long and 

 slender, maxillary armature extending only half way down, 



male without lamellae at the posterior ventral area 



genus Amblyomma Koch 



Body like Amblyomma, stigmal plate with an overlapping corner, 

 maxillary armature extending to the base of the maxillae, male 



with prominent lamellae at the posterior ventral area 



genus Hyalomma Koch 



The genus Ixodes L,atr. seems to be originally a European 

 form, since it is there represented by numerous species and ap 

 pears to be in many regions the sole representative of this sub 

 order. In the Western Hemisphere, so far as is known, it occurs 

 only in North America, and is here represented by two species. 



The genus Amblyomma on the contrary appears to be essen 

 tially American, and its many often brightly-colored species are 

 found abundantly in both North and South America. 



The genus Hyalomma inhabits principally Africa, but a spe 

 cies has been found on a Land- turtle in England, one from the 

 Galapagos Islands (host unknown), and a third one upon a 

 Land-turtle from Florida (Indian River). 



Family RHIPISTOMID^. 



j Capituluni drawn out laterally into a sharp point. Eyes present. ...2 



' ( Capitulum with straight sides. Eyes sometimes wanting 3 



f Second and third palpal joints drawn out laterally into a sharp point. 



genus Boophilus Curt. 



2 ' j Second and third palpal joints straight, not drawn out 



genus Rhipicephalus Koch. 



