384 



BUEEAU OF ANIMAL mDUSTRY. 



nized by various authors as representing a distinct family, superfamily, 

 suborder, and order. To our minds Banks's proposition of a super- 

 family seems the best, hence it is adopted here. 



This superfamily may be divided into two families — Argasidie and 

 Ixodidae. 



The family Argasidae (p. 400) is composed of two genera — Argas 

 and Ornitkodoros — while the family Ixodidfe (p. 414) may be further 

 subdivided into the two subfamilies Rhipicephalinje, with the four gen- 

 era RMjnceplialus^ BoopMliis^ II(e)na2)hysal?s^ and Dermacentor^ and 

 Ixodinae, with the five genera Ixodes^ Escliatoceplialm^ Aponomma^ 

 Amhlyomma^ and Ilyalomma. 



All of these groups may be readily distinguished b}^ the following- 

 ke}^ : 



Key to the Families, Subfamilies, and Genera of the Super- 

 family IXODOIDEA. 



[For genera already reported on cattle in the United States, follow Roman type.] 



1. Scutum absent Argasida?, 2. 



Scutum present Ixodida3, 3. 



Family Argasid.e. 



2. Capitulum removed by at least its length from the anterior 



margin; body rounded anteriorly, without a projecting 



beak-like prominence; eyes absent Ar(/as^ p. 401. 



Capitulum hidden under a projecting beak-like prominence 

 (hood), so close to anterior margin that the tips of the 

 palpi project from under the body and are visible from 

 above; eyes present or absent Ornitkodoros^ p. 407. 



Family Ixodid.e. 



3. Palpi short, subtriangular, not or only slighth^ longer than 



broad; capitulum short; front of bodv emarginate for 



insertion of capitulum JRliipiceplialiriiiu 4. 



Palpi longer than broad; capitulum long; front of body- 

 Straight or emarginate IxodhuP,^ 7. 



Ward, 1900a, pp. 193-205.— Idem, 1900b, pp. 430, 435-437.— Stiles & Habsall, 

 1901, p. 1. [See also Trouessart, 1891, pp. 291, 294, :301, 305, 308.] 



1876: Fam. Ixodklh Megnin, 1876, p. 293.— Idem, 1877, p. 86.— Idem, 1880, pp. 117- 

 136.— Eailliet, 1886, pp. 495-502.— Idem, 1893, pp. 703-718.— Neumann, 

 1888, pp. 82, 87-96, 219-221.— Idem, 1892a, pp. 90, 91, 92-101, 221-223.— Ib^m, 

 1896, pp. 1-44.— Idem, 1897, pp. 324-420.— Idem, 1899, pp. 107-294.— Blanch- 

 ARD, 1890, pp*. 322-339. 



I^r76: Fam. Ixodse AVagxer, 1876, p. 129. 



1892: Order 3Ietastiginata Oanestrini, 1892, pp. 580-582, 587. Probably earlier. [See 



also Trouessart, 1892, p. 28.] 

 1892: Suborder Ci/norluv.^tea Marx, 1892, pp. 233-236.— Morgan, 1899, p. 136. 

 1894: Superfam. Ixodoklea Banks, 1894, p. 209.— Salmon & Stiles, 1901, pp. 383-488. 



