XVI 



ILLUSTRATIONS 



FIG. 



24- 



[25. 

 [26. 

 [27. 

 [28. 

 [29. 

 [30. 

 ;i- 



'33- 



'34- 

 '35- 

 [36. 

 '37- 

 [38- 



'39- 

 140. 



[41. 



[42. 



'43- 

 [44. 

 [45. 

 146. 



147- 

 [48. 

 [49. 



[50. 

 [51. 



[52. 



'53- 



^54- 



'55- 

 [56. 



[ 57- 



: 5 8. 



[ 59 . 

 [60. 

 [6l. 

 [62. 

 I6 3 . 

 [6 4 . 

 ,6 5 . 



[66. 

 [67. 

 168. 



Lingula ..... 



Nereis dumerilii.) partially dissected 



Nereis dumerilii, natural size 



Polyiine setosissima 



Aphrodite aculeata 



Trochophore larva 



Autolytus cornutus 



Serpula 



Lumbricus terrestris 



Myzostoma . 



I 'olygordius neapolitanus 



Priapitltts 



Bonellia viridis 



Hirudo medicinalis, anatomy 



Hirudo. cocoon 



Diagrammatic cross section of abdomen 



Apus, development 



Apits cancriformis 



A pits glacial is 



Various Phvllopoda 



Daphnia si 111 His . 



Cypris Candida 



Cyclops 



Various parasitic Copepoda 



. Irgulus foliaceus . 



Lepas anatifera . 



Balanus 



Sacculiiia carcini . 



Nebalia geoffroyi . 



Asellus aquations . 



Porcellio si aber 



Gammarus neglectus 



Various Amphipoda 



Plasty I is stygia 



Sq it ilia 



Mysis oculata 



A si iic us fluviatilis 



Crangon : Palcemon 



Pagurus bernhardus 



Cancer pagurus . 



Various crabs 



Larvae of crabs 



Limulus polypheinits 



Li/iiulits. larva 



Valuta 11 ites socialis ; Phacops fecundus 



of lobster 



'34 

 '35 

 '36 

 ^37 

 ^37 

 '38 

 '38 



'39 

 [40 



141 

 [42 



'43 

 143 

 '44 



'45 

 '47 



'49 

 [50 



[50 



[ 5' 

 [52 



[ 53 



'54 

 f 55 

 '56 

 '57 

 : 5 8 

 ,58 

 [60 

 [61 

 [62 

 162 



'63 

 .65 



'65 

 [66 

 [67 

 [68 

 ,69 

 170 

 [71 

 [72 



<-73 

 '74 

 1-4 



