PARASITOLOGY. 17 



the head parts more prominent. The dorsal shield 

 is large, somewhat elongated through the antero- 

 posterior diameter, and is white in color. The hy- 

 poscome is provided with six rows of denticles. The 

 dorsal surface of the male presents a large, white 

 dorsal shield and silvery markings. 



Dermacentor Reticulatus. 

 History. — Found particularly in the Rocky Moun- 

 tain region. 

 Animal Infested. — The ox. 



Description. — The tick is about the size of the der- 

 macentor electus. Its dorsal shield is large and a 

 rusty white in color. The stigmal plate differs in shape 

 from the D. electus as shown in the illustration. 

 Amblyomma Americanum (American), 



Syrionym. — Lone Star tick; Amblyomma una- 

 puncta. 



Distribution. — Southern United States and South 

 America. 



Animal Infested. — The ox. 



Description. — About the same size as the preceding 

 described tick. The dorsal shield is triangular ic 

 shape and reddish brown ; it is marked with a white 

 spot in the posterior border. The head parts are 

 more prominent than in the Boophilus Annulatus. 

 The hypostome is furnished with six rows of denti- 

 cles. 



LINGUATULIDA. 



This order includes a group of degraded Acari, 

 the most common of which is the 



LiNGUATULA Rhinaria (Lingua — tongue). 

 Synonyms. — Pentastoma Taenoides ; Linguatula 



