52 Addison E. Verrill, 



(pi. 18, fig. 6) and undergo extensive metamorphoses, passing 

 through protozoea and zoea stages. (See Brooks, op. cit, 1882.) 



Leucifer H. Milne-Edw.* 



Lucifer V. Thompson, Zool. Res., p. 58, pi. vii, fig. 2, 1869 (name pre- 

 occupied). W. K. Brooks, op. cit., vol. 173, pp. 57-157, structure and 

 development, 1883. Bate, op. cit., pp. 442-467, pi. 79-85, structure and 

 development, 1888. 



Leucifer H. M.-Edw., Hist. Crust., ii, p. 469, 1837. Dana, op. cit., p. 

 662. 



TEXT FIGURE 4. PLATES XVII and XVIII. 



Integument thin, transparent. Cephalic region or neck (cepha- 

 lon) long, cylindrical ; pleon very long, about two thirds of 

 body ; its sixth segment much longer than the others, which 

 are subequal; pleopods long; uropods large, branches unequal, 

 usually much longer than telson. Telson small, narrow, tapered, 

 with three spines at each angle and, in the male a ventral lobe; 

 four spinules above. 



FIGURE 4. Leucifer. sp. ?; a, antennule; b, antenna; o, eye; ot, ootocyst; 

 s, antenna! scale. Enlarged. 



Eye-stalks long ; eyes large ; ootocysts well developed. Anten- 

 nules with a slender three- jointed peduncle and a single slender 

 flagellum. Antennae have a long flagellum and a narrow subacute 

 scale; basicerite small, bicuspid. A clasping organ (petasma) on 

 anterior side of first pleopods of male and the second pleopod has 



* The name of this genus was first written Lucifer. It was changed to 

 Leucifer by M.-Edwards, but he gave no reason for the change. It has 

 been said that it was because the former was preoccupied, but as he quotes 

 Thompson as spelling it Leucifer, he probably intended it as a more correct 

 form. However, as Lucifer was really preoccupied, the change should be 

 adopted. 



