xxii ILL USTRA TIONS 



riGUEu Page 



66. Paradoxides spinosus, Cambrian, Bohemia ; pygidium and six 



free segments 79 



66. Female of Lernceascus nematoxys, a parasitic copepod ; showing 



suppression of limbs . • • 85 



67. Horse-shoe Crab (Limulus polyphemus) \ showing telson spine 



and abbreviated abdomen .... 85 



68. A Devonian phyllooarid {Echinocaris socialis) ; showing spini- 



form telson and cercopods .... 85 



69. Wing of Apieryx australis . . 85 



70. Skeleton of right fore limb of the Jurassic Dinosaur Iguanodon 



hernissartensis ; showing suppressed first digit 85 



71. Leaf of Katan (Dcemonorops hygrophilus) 89 



72. Leaf of Ratan (Desmoncus polj/canlhus) ... ... 89 



73. Bramble (Rubus squarrosus) 89 



74. Diagram and table ; showing correlation of stages and conditions 



of development in the spinose individual, in its ancestry, 



and in time ....... ... . . 100 



75. Table of geological distribution of Trilobita 133 



76. Agnostus nudus Beyrich . 177 



77. Agnostus rex Barrande . 177 



78. Trinucleus ornatus Sternberg 177 



79. Hydrocephalus satwnoides Barrande 177 



80. Hydrocephalus carens BsLTrande . 177 



81-83. Olenellus {Mesonacis) asaphoides Emmons 177 



84. Geological range and distribution of Arthropoda 184 



85-94. Cistella neapolilana Scacchi 248-250 



95-98. Spirorbis horealis Daudin 253 



99, 100. Cistella neapolitana Scacchi 254 



101-107. Thecidium (Lacazella) mediterraneum Kisso 258 



108-113. Cistella neapolitana Scacchi .... . . 261 



114. Delthyrium of young Rhynchonella, without deltidial plates . . 262 



115. The same at a later stage, with two triangular deltidial plates . 262 



116. The same after completed growth ; showing joining of deltidial 



plates, and limitation of pedicle-opening to ventral beak . 262 



117. Dorsal view of Magellania flavescens ; showing completed 



deltidial plates (del) 262 



118. The same; profile 262 



119. Dorsal view of umbonal portion of adult Terebratulina septen- 



trionalis, with shell removed by acid ; showing slight sec- 

 ondary extension of ventral mantle around pedicle . . 262 



120. Dorsal view of umbonal portion of Magellania flavescens, with 



the shell removed by acid ; showing the complete envelop- 

 ment of base oE pedicle by secondary expansions from ven- 

 tral mantle, and consequent ]irodiiction of deltidial plates 

 filling delthyrium except at pedicle-opening 262 



