448 BUREAU OF ANIMAL INDUSTRY. 



Neumann's key is here added, as it contains other forms: 



Key to the Species op the Genus Dermacentok.^ 



[For forms reported in the United States, follow Roman type.] 



Females 1 



Males 5 



A.— Female. 



1 . Scutum marked with white spots 2 



Scutum marked with red or yellow spots 4 



Scutum not marked with light spots, blackish (Porto Rico) D. nitens. 



2. Scutum nearly as broad as long; second palpal article with dorsal retrograde 



prolongation D. reticulatus, p. 448 



Scutum longer than broad; second palpal article without prominent dorsal 

 retrograde prolongations 3 



3. Body oval; hairs few D. electus, p. 455 



Body oblong; hairs abundant D. variegatus, p. 452 



4. Scutum nearly covered with light spots (Africa) D, rhinocerotis. 



Scutum with three spots arranged in a triangle (Congo) D. circumguttatus. 



B.—Male. 



5. Scutum marked with white spots 6 



Scutum marked with red or yellow spots 8 



Scutum of uniform color, vnthout spots 9 



6. Second palpal article very much swollen laterally, with dorsal retrograde 



spine D. reticulatus, p. 448 



Second palpal article slightly swollen laterally, without dorsal retrograde 

 spine 7 



7. Body oval D. electus, p. 455 



Body triangular D. variegatus, p. 452 



8. Spots on scutum symmetrical; one large arrow-shaped spot anteriorly, representing 



a pseudo-scutum (Africa) B. rhinocerotis. 



Four pairs of symmetrically arranged spots on scutum; pseudo-scutum absent 

 (Congo) -D. circumguttatus. 



9. Scutum pubescent; palpi not swollen (Porto Rico) D. nitens. 



Scutum glabrous; palpi swollen laterally (Syria) D. parvus. 



The Net Tick {Dermacentor reticulatus).^ 



(Figures 61, 169-177.) 



Specific diagnosis. — J)ermacentor: Stigmal plate coarsely punctate. 

 Male. — Body same form and dimensions as young female, occasionally larger. 

 Scutum deep reddish brown, but concealed for the most part by a silver white 



^ The following species are not included in this key: D. 2mncticollis, dentipes, cl<i- 

 thratus, parabolicus, cruentus; all Koch, none American. D. planus Rudenow. ]) 

 Feai, auratus, indicus, longipes Supino; apparently not American. 



2 Synonymy and Bibliography. 



1704: Acarus reticulatus Fabricius, 1794, p. 428. [See also Latreille, 1804, p. 52; 



Railliet, 1893, p. 713, and Neumann, 1897, p. 360, as syn. of Dermacentor 



reticulatus.— Fabhicivs, 1805, p. 355, as syn. of Ixodes reticulatus.] 

 1806: Ixodes reticulatus (Fabricius) Fabricius, 1805, p. 355.— Latreille, 1806, p. 



157.— Idem, 1829, p. 288.— Illiger, 1807, p. 369.— Moquin-Tandon, 1861, p. 



303. [See also Gervais, 1844, p. 240, as syn. of Ixodes pictus.] [See also 



