1881. ] Variations in a Copepod Crustacean. 693 
_ base of the main mandibulary palpus is delicately bristled exte- 
riorly only. Three smaller cilia are found above the latter on a 
small protuberance. 
The mandible in all Copepeda originates from the third larval 
leg, which is already in the “ Nauplius stage,” provided with a 
dentate mandibular process. In the family of Calanide, the man- 
dibulary palpus is 
comparatively lon- 
ger than in the 
other five families 
of Copepoda. 
The maxilla (Fig. 
5) is quite a com- 
plicated structure, 
consisting of sev- 
eral lobes, the ex- 
planation of which 
is found below the 
cut. The maxillz 
are the second pair ‘ewes 
of oral organs, and. 21 Sj Milne eet ela 
originate from the palpus; Ff, posterior lobe, or secondary branch of palpus. 
bristled and lobed Enlarged about 300 x. : 
appendages of the larva, and these occur behind the third nata- 
tory leg, or future mandibulary palpus. eee 
Another minute mouth-piece is the superior or first a. 
(Fig. 6). It is somewhat sub-jointed, elongate, and bears fifteen 
bristles as the illustration shows. Both the 
Superior and inferior maxillipeds are the 
Separately diverging branches of a single 
Pair of limbs originating out of the fifth 
pair of legs of the later “ Nauplius stage,” 
and are in the adult, with a few exceptions, 
dissimilarly inserted, the outer branches of 
those legs being transformed into the supe- 
rior, the inner branches into the inferior 
ee ds. + Fic. 6.—Superior or first 
We now take a look at Fig. 7, represent- maxilliped. Enlarged about 
ing the inferior or second maxilliped. Its 4% mn 
basal segment presents in our species four rounded processe 
