TABLE OF CONTENTS. xi 



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, Raja batis : heart, brain, Elasmobranch embryo . . 273 



V. Cellar Slug, Limaxflavus 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 Cicindela 

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

 limb of Scolopendra morsitans, Epeira fasdata, digestive 

 organs of Tegenaria domestica, Nauplius of Lepas fasci- 

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



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



XL Common Starfish, Asterias rubens ... .311 



XII. Earthworm, Lumbricus terrestris ... . 315 



,, XIII. Medicinal Leech, Hirudo medidnalis . . . .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 

 P/umuiaria, two nematocysts of Millepora, one discharged, 

 the other not 326 



