KNIGHT: STAGES OF THYSANOPODA TRICUSPJDATA 



a 



f 



0.1 mm 



Figure 6. — Mandible: a, nauplius, right, anterior view; b, metanauplius, left, posterior view. 

 Mandibles, posterior view: c-e, calyptopes I-III; f, right mandible of calyptopis II rotated to show 

 relative length of triangular lateral process. 



Antennule (Figure 4c) 2-segTnented ; proto- 

 pod long and slender with small terminal seg- 

 ment forming outer flagellum which bears about 

 9 terminal processes including 2 long setae, 2 

 aesthetascs (one of these is situated slightly 

 subterminally on outer margin), and about 5 

 spinous processes of varying sizes; there is rudi- 

 ment of inner flagellum bearing 1 long seta and 

 3 spinous processes; a small spine is situated 

 at base of inner ramus, and there is 1 seta and 

 1 or 2 small spines dorsally on distal margin of 

 protopod at base of outer flagellum. 



Antenna (Figure 5c) now with form found in 

 calyptopis stages I-III; endopod with 4 long 

 terminal setae and 2 setae on inner margin, prox- 

 imal seta still relatively short; exopod with 7 

 plumose setae, the terminal segment now bears 

 3 setae; coxa and basis without spinules. 



Mandibles (Figure 6c) rudimentary, with 

 large lateral process, medial margins smooth ex- 

 cept for 1 small incisor tooth on each mandible. 



Maxillule (Figure 7b) armed only with rudi- 

 mentary small spines; endopod of 1 segment 

 with 3 spines; exopod a very small lobe bearing 



61 



