On the Young Stages of a few Annelids. 343 



Fig. 44. Hook-shaped stiff bristles of the lower side. 



Fig. 45. Posterior extremity of Nerine. 



Fig. 46. Young Phyllodoce from the dorsal side. 



Fig. 47. (n. f.V Figure 46 seen in profile. 



Fig. 47. (1. f.) The tentacles of the anterior part of the Phyllodoce have 

 developed. The body has considerably lengthened ; seen from the dorsal 

 side. 



Fig. 49. The same seen from the mouth side. 



Fig. 50. Young Phyllodoce, seen in profile in stage of Fig. 47. (1. f.) 



Fig. 51. Somewhat older than the preceding stages; seen from above. 



Fig. 52. Young Phyllodoce in which the body has greatly elongated ; 

 seen from above. 



Fig. 53. Head of adult Phyllodoce maculata, from above. 



Fig. 54. Paddle and seta3 of adult of figure 53 ; seen in profile. 



Fig. 55. Anal extremity of the same. 



Fig. 56. Embryo Annelid, with immense bunches of temporary bris- 

 tles. 



Fig. 57. Adult of figure 56. ? ? 



Fig. 58. Minute Annelid parasitic on shell of lobster. 



INDEX. 



PAGE 



Planaria, 306 



Loven's Larva, " 309 



Spirorbis Spirillum, 318 



Tkrebella Fulgida, 320 



POLYDORA, 323 



Nerixe, 330 



PnYi.LonocE Maculata, 333 



Types of Development, ......... 336 



Explanation of Figures, ' . 340 



