OF DENISON UNIVERSITY. 
23 
jF/^\ 6. Lower view of anterior part of a larva, about the size of that shown 
in figure 2, oc. nauplius eye ; Ai, antennse ; e, eye ; upper ganglion ; ^i, optic 
lobe ; A 3, swimming antennge (base only shown); M, mouth opening, bordered on 
either side by commissures passing to the infra-oesophagal ganglion ; L, labrum ; 
Md, mandible and palp ; Mx, first maxilla ; Mx 2, second maxilla ; //, III, IV, 
etc., feet in different stages of development. 
Plate VI. 
Fig. I. Chirocephalus larva in an advanced stage, seen from above. 
Fig. 2. Limneies goiddii, early stage, 
Fig. 3. First right swimming foot of Chirocephalus when 1,4 mm. long. 
Figs. 4-6. First, sixth, and ninth feet of younger larva. 
Fig. 7. Abdomen of same. 
Plate VII. 
Fig. I. Larva of Liumetes .33 mm. long. A, first antennae ; A 2, swimming 
anteniiEe; Md, mandiblar palp, e, eye; /, lense ; L, liver, budding from anterior 
part of stomach ; j-, sensory filament ; in, muscles of rectum. 
Fig. 2. Larva of Chirocephalus, from below. 
Fig. 3. Caudal stylet of same. 
Fig. 4. Flead, showing organs of one side, L, liver. 
Fig. 5- Muscles of swimming antennae. 
Fig. 6. Maxilla. Fig. 7. End of abdomen of an older individual. Fig. 
8. Mandible and palpus (/) in this stage. Fig. 9. Antennae of female. Fig. 
10. Antenna of male ; /; inner ramus ; g, frontal organ. 
Fig. II. Part of Limnetes older than figure i. 
Fig. 12. First abdominal segment of female, seen from below. 
Plate VIIL 
Fig. I. Head of male approaching maturity. 
Fig. 2. Antenna of female, (length of antenna .78 mm.) 
Fig. 3. Antenna of male of about the same age, (length of antenna .79 mm.) 
Fig. 4. Fourth foot of male ^ inches long. 
Fig. 5. Abdomen of young male. 
Fig. 6. Caudal stylets of same, (.78 mm. long.) 
Fig. 7. Antenna of same. 
Fig. 8. Copulatory organs of one side, m, muscle common to the sheaths of 
both male organs ; p, penis or forceps ; t. testis. 
Fig. 9. End of sensory antenna ; a, sensory rods, enlarged. 
■Fig. 10, Yiqw Qf tliQ surface of the basal knob on the male antenna. 
