92 MR. W. K. BROOKS ON LUCIFER: 



IV. HISTORY OF THE APPENDAGES OF LUCIFER. 



For convenience of reference I will now describe the changes which each appendage 

 undergoes at each stage of development, going over the same ground once more, but in 

 a different way. 



The first antenna. 



In the egg Nauplius (figs. 21, 23, and 24,^4) this appendage is unjointed, more than 

 half as long as the body, and it carries a terminal tuft of hairs. 



In the first free Nauplius (6g. 25, A) it consists of five nearly equal joints; it is 

 nearly as long as the body of the second antenna, and its tip carries two long simple 

 hairs and two much smaller hairs. 



In the last Nauplius stage, or metti-Nauplius (fig. 2G) the joints have disappeared ; 

 it is only about two-thirds as long as the body, and it carries only the two long hairs 

 at the tip. 



In the first Protozoea stage (fig. 27, A) it is made up of a long cylindrical basal joint 

 with a few short hairs, arid a much shorter terminal joint, which is pointed, and carries 

 the two long hairs as before. 



The structure of the appendage does not change until the end of the Zo&a series, 

 and it is shown at A in figs. 34, 42, 43, and 44. 



At the first Schizopod stage (fig. 50, A) the basal portion is made up of one very 

 long cylindrical joint, with a hook near its swollen base, and a much shorter distal 

 joint. Three long, two-jointed, plumose hairs spring from the inner edge of the second 

 joint, and three more from the inner edge of the distal third of the basal joint. The 

 terminal portion has lost the two long hairs which it had at earlier stages. 



In the last Schizopod stage (fig. 54, A, and fig. 56) the distal third of the basal 

 joint has separated off as a distinct joint (fig. 56, 2) upon which the tliree hairs are 

 situated. The ear has made its appearance, behind the hook, on the swollen base of 

 the first joint. The terminal joint (4) carries three sensory hairs, which arise upon its 

 outer surface about half way between its tip and base. 



In the Mastigopus stage (fig. 60) the terminal joint has lengthened to form a two- 

 jointed flagellum, and the appendage is more than twice as long as the eye. 



In the young specimens which have attained to the adult form (fig. 61, A) the 

 appendage is about as long as the carapace and neck, and in the adult (fig. 66, A) the 

 flagellum (2) is about as long as the basal portion (1). It consists of ten joints, the 

 terminal one longest, and the first and second thick. The first carries two and the 

 second three sensory hairs. 



The basal portion is thick, cylindrical, three-jointed, with six plumose hairs, and the 

 ear nearly fills the enlarged base. 



