Phylum Arthropoda 515 



Fig. 171. — Arachnids and related forms, a, A pycnogonid or sea spider; b, a 

 solupugid; c, an opilionid; d, a pseudoscorpion, e, a scorpion; /, a centipede; g, a 

 linguatulid or tongue worm; h, a tardigrade or water bear i, a symphylid; j, a pauro- 

 pod, k, a whip scorpion; I, a tick, Dermacentor; m, a millipede; n, female black widow 

 spider Latrodectus, ventral view; o, the itch mite, Sarcoptes. 



