LINGUATULTDA 455 



the plant tissues, on the juices of which the animal usually lives: on 

 plants and the ground, often a pest in greenhouses; about 6 American 

 genera, with 20 species. 



1. TETRANYCHUS Dufour. Pedipalps short, ending with a thumb- 

 like projection; the animals are able to spin a web, by means of which 

 they fasten the minute red eggs to leaves; first pair of legs longer than 

 the body: about 14 American species. 



Fig. 714 Fig. 715 Fig. 716 



Fig. 714 Rhyncholophus macuJatus (Banks). Fig. 715 Tetranychus bimaculatua 

 (Banks). Fig. 716 Bryobia prate nsis (Banks). 



T. bimaculatus* Harvey (T. cucumeris Boisduval) (Fig. 715). But 

 1 claw on each foot, which splits into 4 near the tip; color and size 

 variable; color usually red, but sometimes yellowish with black dots: 

 often common on vegetables and cultivated flowers, both in greenhouses 

 and out of doors. 



2. BRYOBIA Koch. Body with scale-like hairs above: 1 American 

 species. 



B. pratensis Garman (Fig. 716). The clover mite. Body red with 

 4 scale-like hairs projecting in front; first pair of legs longer than the 

 others : often numerous on clover and fruit trees ; eggs red, on fruit trees 

 in winter; they often hibernate in houses, and may become a nuisance. 



ORDER 9. LINGUATULIDA.J 



Worm-like arachnids (Fig. 717, A), in which the abdomen is very 

 much elongated and composed of a large number of short rings, which 



* See "The Common Red Spider (Tetranychus bimaculatus) ," etc., by F. H. 

 Chittenden, Cir. 29, Div. of Ent., U. S. Dept. of Agr., 1909. 



t See "Contribution to Helminthology," by J. Leidy, Proc. Acad. Nat. Sci., Phila., 

 Vol. 5, p. 96. "A Synopsis of Entozoa," etc., by the same, same, 1856, p. 42. 

 "Description of Pentastomum prob.," by the same, same, 1884, p. 140. "Bau u. 

 Entwick. von Pentastomum," etc., by C. W. Stiles, Zeit. f. Wiss. Zool., Bd. 52, 1891. 

 "An Attempt to Revise the Family Linguatulidae," by A. E. Shipley, Arch, de 

 Parasit., Vol. 1, p. 52, 1898. 



