Index. 
33 
River-Crabs, 72 
Robber-Crab, 61 (fig.) 
Rostrum of Acari, 109 ; 
of Crustacea, 13 
S. 
Sacculina, 23, 35 (fig.) 
Salticidae, 101 
Sand-Crabs, 66 
Sandhopper, 45 
Sarcoptes, 113 (fig.) 
Scalpellum, 33 
Sclerocrangon, 53 
Scolopendra, 127 (fig.) 
Scolopendrellidae, 125 
Scolopendromorpha, 126 
Scorpiones, 84 
Schendyla, 126 
Schizomus, 89 
Schizopoda, 49 
Scutigera, 128 (fig.) 
Scutigerella, 124 (fig.), 125 
Scutigeridae, 128 
Scutum, 33 
Scyllaridae, 56 
Scyllaridea, 56 
Scyllarus, 56 
Scytodes, 91 
Sea-spiders, 11 
Segestria , 101 
Segment, 13 
Seothyra, 101 
Serrula, 105 
Sesarma, 74 
Sexual differences of Crus- 
tacea, 19 
Shore Crab, 22 (fig.), 35, 44, 
71 
Shorehopper, 45 
Shrimp, 51 ; Arctic, 53 ; 
common, 53 ; pink, 52 
Sicariidae, 91 
Sicarius , 91 
Silk-glands, 105 
Siphonophora, 122 
Siphonophoridae, 122 
Sironidae, 108 
Slaters, 43 
Snares, 97 
Social Spiders, 101 
Solifugae, 102 
Solpuga, 104 
Solpugidae, 104 
Somite, 12 
Spawning of Lobster, 20 
Sperm receptacle, 20 
Sphaeromidae, 42 
Sphaer other ium, 121 (fig.) 
Spiders, 91 
Spider-Crabs, 68 
Spinnerets, 91, 93, 94, 96 
Spinning-mites, 112 
Spirillosis, 111 
Spirobolidae, 123 
Spirostreptidae, 123 
Sguilla, 47, 48 (fig.) 
Stegocephalus, 46 
Stegodyphus, 101 
Stenopidea, 51 
Stenopus, 51 
Sternum of Crustacea, 14 ; 
of Trilobita, 78 
Stink-glands, 107, 120 
Stomatopoda, 47 
Stone-Crab, Northern, 
62 (fig.) 
Streptocephalus, 26 
Stridulatory organs, 91, 
127 ; ridges, 103 
Stylocellus, 108 (tig.) 
Stylonurus , 84 
Swimmerets, 13 
Swimming Crabs, 70 
Symphyla, 9, 124 
Syncarida, 37 
T 
Tachypleus, 82 
Tail, 87 
Tail-fan, 51 
Talitrus, 45 
Tanaidacea, 40 
Tarantula, 100 
Tarantulidae, 90 
Tarsal comb, 98 (fig.) 
Tartarides, 89 
Ta smanian Crab, 23, 71 (fig.) 
Tegenaria, 100 
Telson, 13 
Tergum, of Trilobita, 78 ; of 
Crustacea, 14 ; of Cirri- 
pedia, 34 
Testis of Crustacea, 19 
Tetranychinae, 112 
Tetranyclms, 112 
Tetrapoda, 114 
Texas fever, 111 
Thalassina, 59 
Thalassinidea, 59 
Thelphusa, 72 
Thelphusidae, 72 
Thelyphonus, 88 (fig.) 
Theraphosa, 94 
Theridiidae, 92, 98 
Theridion, 98, (fig.) 
Thomisidae, 99 
Thompson, 31 
Thorax of Crustacea, 14 
Ticks, 109, 110 
Tick-fever, 111 
Toxicognaths, 125 
Tracheal tubes, 43, 91, 96, 
119, 120, 121, 122, 125 
Trap-door nests, 95, 100 ; 
spiders, 95 
Triaenonychidae, 108 
Triarthrus, 77 (fig.), 79 
Trilobita, 9, 77 
Trithyreus, 89 
Trogulidae, 108 
Trogulus, 108 
Trombidiidae, 112 
Trombidium, 112 
Tubicinella, 34 
Turrilepas, 33 
Tyroglyphus, 113 
U 
Uca, 74 
Urodacus, 86 
Uropod, 15 
Uroptychidae, 63 
Uropygi, 87 
Urotricha, 87 
V 
Valvifera, 42 
Varuna, 74 
Vejovidae, 86 
Vejovis, 87 
Vermiformia, 114 
W 
Waddington, 21 
Water-fleas, 27 
Water-mites, 112 
Water-spiders, 101 
Webs, 97 
Whales, Cirripedes on, 34 
Whale-lice, 47 
Whip-scorpions, 87 
Wolf-spiders, 100 
Woodlice, 43 
Wood-Mason, 91 
X 
Xanthidae, 70 
Xantho, 70 
Xenesthis, 94 
Xiphosura, 11, 81 
Xiyhosura, 82 (fig.) 
Z 
Zozymus, 70 
Zephronia, 122 
Zephroniodesmus, 122 
