Vill INTRODUCTION. 
Fam. HYDRACHNID. 
Gen. ATAx. 
Palearctic Region (Europe). 
Nearctic R. (U.S.A.). 
Neotropical R. (Mexico*, Guatemala). 
AKthiopian R. (East Africa +). 
Gen. Nesaa (Curvipes). 
Palearctic Region (Europe, Bering’s Island). 
Neotropical R. (Mexico, Guatemala). 
fKthiopian R.: East Africa t. 
Gen. LiMNzsia. 
_ Palearctic R. (Europe). 
Nearctic R. (U.S.A.). 
Neotropical R. (Guatemala). 
fKthiopian R. (German East Africa t). 
Fam. BDELLIDA. 
Gen. BpELLA. 
Palearctic Region (Europe, N.E. Siberia, Bering’s Island). 
Nearctic R. (U.S.A.). 
Neotropical R. (Guatemala, Brazil, Paraguay, La Plata). 
Fam. EUPODIDA. 
Gen. ScyPHius. 
Palearctic Region (Europe, N.E. Siberia, Japan). 
Neotropical R. (Guatemala). 
Fam. IXODIDZ. 
Gen. Ixopzs. 
Palearctic Region (Europe, Bering’s Island). 
Nearctic R. (U.S.A.). 
Neotropical R. (Central and South America). 
fEthiopian R. (South Africa [¢este C. L. Koch] ). 
Gen. AMBLYOMMA. 
Nearctic Region (U.S.A.). 
Neotropical R. (Central and South America). 
Oriental R. (Java, Philippine Islands, Bintang, Continental India [teste C. L. Koch ]). 
* Toe Mexican species described by M. Alfred Dugis as Atax alzatei belongs, according to a private 
communication of Herr F. Koenike, to the genus Nesea. 
t Herr F. Koenike, the well-known specialist in this group, writes me that he possesses specimens of Ataw 
collected by Dr. Stuhlmann during his expedition with Emin Pasha. 
¢ According to the above-quoted communication of Herr F, Koenike. 
