TABLE OF CONTENTS. x i 



DESCRIPTION OF PLATES. 



PAGE 



Plate I. Common Rat, Mus decumanus 261 



II. Common Pigeon, Columba livia ...... 265 



III. Common Frog, Rana temporaria . . . . . .269 



IV. Skate, Rajabatis-. heart, brain, Elasmobranch embryo . . 273 



V. Cellar Slug, Limaxftavus s. variegatus 281 



,, VI. Fresh-water Mussel, Anodonta cygnea . . . . .285 



VII. Lamellibranchiata : i. e. Ostrea edulis, its digestive tract, heart 

 of Area Noe, diagram of a left nephridium, Veliger of Car- 

 dium pygmaeum . . . , . . . . .289 



VIII. Common Cockroach, Periplaneta orientalis .... 295 



>, IX. Arthropoda, i. e. Machilis polypoda, mouth-parts of Cidndela 

 litloralis, same of Apis mellifica, mouth-parts and ambulatory 

 limb of Scolopendra morsitans^ Epeira fasciata, digestive 

 organs of Tegenaria domestica, Nauplius of Lepas fasci- 

 cularis .......... 299 



X. Common Crayfish, Astacus fluviatilis, male .... 307 



,, XI. Common Starfish, Asterias rubens . . , . . .311 



,, XII. Earthworm, Lumbricus terrestris ... 315 



,, XIII. Medicinal Leech, Hirndo medirinalis ... .319 



XIV. Cestoda, i. e. Tapeworm, unripe proglottis, uterus of ripe 



proglottis, proscolex, cystic Coenurus cerebralis . 323 



Hydroidea, i. e. Hydra viridis, tentacle of Eucopella, sense-cell, 

 supporting-cell, cnidoblast, ganglion-cell of a guard polype of 

 Plumularia, two nematocysts of Millepora, one discharged, 

 the other not .... 326 



