ANTENNA (Fig. 2B). — Flagellum styliform, 

 about same length as antennal scale, tipped by 

 short spine. Antennal scale about 3.5 times as 

 long as wide, fringed with 15 plumose setae along 

 terminal and medial margins. Antennal scale 

 with four joints distally (proximal joint incom- 

 plete), lateral projection on distal portion. Tip of 

 antennal scale not curved laterally as in Stage I. 

 Protopodite with spine at base of flagellum. 



MANDIBLES. — Same as in Stage I except have 

 slightly developed molar lip. 



MAXILLULE, MAXILLA, AND MAXILLIPEDS. 

 — Similar to Stage I except scaphognathite of 

 maxilla has six setae; exopodites of maxillipeds 

 1-3 have 5, 8, and 10 natatory setae, respectively. 



PEREOPODS.— Slightly larger than in Stage I, 

 extend somewhat vertically, have naked exopo- 

 dites on pereopods 1 and 2. 



PLEOPODS. — Absent. 



ABDOMEN AND TELSON. — Posterolateral 

 spines on abdominal somites 4 and 5 nearly same 

 length. Telson (Fig. 2C) still fused with ab- 

 dominal somite 6, has 8 + 8 densely plumose 

 setae. Enclosed uropods somewhat longer than in 

 Stage I. 



Stage III Zoea 



Mean total length of Stage III zoea, 4.1 mm 



(range 3.9-4.3 mm; two specimens). Carapace 

 identical to Stage II carapace, except has supra- 

 orbital spine. 



ANTENNULE. — Similar to Stage II antennule 

 except outer flagellum has subterminal seta, 

 proximal segment with four setae around distal 

 joint and three plumose setae laterally, distal 

 segment with four large plumose setae. 



ANTENNA, MANDIBLES, MAXILLULE, AND 

 MAXILLA. — Similar to Stage II but with follow- 

 ing differences. Antennal scale, without joints 

 terminally, has 20 plumose setae along terminal 

 and medial margins; subterminal spine extends 

 just beyond tip of scale. Mandibles with a few 

 additional teeth between incisor and molar pro- 

 cesses. Maxillule with 9 spinulose spines on coxo- 

 podite and 12 short smooth spines on basipodite. 

 Scaphognathite of maxilla has 9-12 plumose 

 setae. 



MAXILLIPEDS. — Exopodites of maxillipeds 1-3 

 have 5, 10, and 10 natatory setae, respectively. 



PEREOPODS (Fig. 3 A, B). — Exopodites only on 

 pereopods 1 and 2; chelae present but undevel- 

 oped; endopodites of pereopods 1 and 2 with 

 terminal seta. 



PLEOPODS. — Present as buds. 



ABDOMEN AND TELSON.— Telson (Fig. 3C), 



0. 5 mm 



B 



FIGURE 3.— Stage III zoea of Spirontocaris murdochi: A, pereopod 1, lateral; B, pereopod 2, lateral; C, telson, dorsal. 



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