34 



THE 



PART I 



as the sensory cirrus of the parapodium of the first 

 segment, the parapodium itself having disappeared, or 

 possibly being represented by the bulb on which the 

 antenna stands ; this latter homology is, however, very 

 doubtful. Though the parapodium itself has dis- 

 appeared, the gland of its aciculum is probably still 

 present, and functions as a salivary gland. Fig. 29 

 p. 114, shows the position and form of this gland. A 

 comparison of this figure with Fig. I will make it 



B 



FIG. 7. A. First antenna (L Spitzbergensis) \v\ti\ hooked sensory hairs, homolo- 

 gous with the olfactory hairs of the higher Crustacea, c, the sensoty cirrus ; d, 

 the bulb on which it stands, perhaps the remains of the dorsal parapodium on 

 which it stood. B. Second antenna (L. Spitzbergensis) showing the rudiments 

 of the endopodite, i.e. of the distal end of the dorsal parapodium which had 

 been highly developed in the Nauplius. but is degenerated in the adult ; c, the 

 sensory cirrus. 



clear that this gland can be so homologised ; the 

 point will, however, be discussed in detail in connec- 

 tion with the description of the gland itself. From 

 Fig. I it will be seen that the acicular gland of the 

 (vanished) parapodium of the first segment could 

 easily open within the mouth, on the under lip. 



