KNICHT and OMORI: LARVAL DF.VF.LOI'MKNT OF SKRCESTES SIMMS 



with armature of stage II, long spine nearest 

 incisor teeth on right mandible separated from 

 other long spines by several small teeth. 



Maxillule (Fig. 6c) with 7 setae on both basal 

 and coxal endites; as in earlier stages distal stout 

 seta on basal endite with long basal spinules, 

 other stout setae with short spinules. 



Maxilla with setation of 9-5-6-5 on medial 

 lobes, rarely with 8 setae on proximal lobe of 

 coxal endite. 



First maxilliped (Fig. 8b) with 9 setae on 

 exopod. 



Second maxilliped (Fig. 9b) with endopod 

 setation of 3-2-2-5 and exopod with 8 setae; coxa 

 with 1 or 2 setae. 



Third maxilliped and thoracic legs 1-5 (Figs, 

 lie, 12a, d) biramous, unsegmented, and 

 nonsetose with exopod slightly longer than 

 endopod. 



Zoea I (Figs. 13, 14a) 



Body length: 3.25 mm (0.13). 



Carapace altered with change in phase, now 

 with 10 spines including rostrum, 1 pair supra- 

 orbital, 1 pair hepatic, 2 pairs lateral, and 1 

 posterodorsal, all spines armed only with 

 spinules except rostrum which bears a strong 

 basal dorsal spine with spinules; dorsal organ 

 present in zoeal phase but smaller than in pre- 

 ceding stages. Eyes with long slender stalk 

 bearing single ventral papilla in both stages of 

 phase. 



Abdomen of 6 segments with following arma- 

 ture: segments 1-5 with 1 pair lateral spines 

 which decrease in length posteriorly, segments 

 1-6 with 1 posterodorsal spine longest on 

 segments 3-5, segment 6 with 1 pair small 

 ventrolateral spines and segment 1 with 1 pair 

 triangular dorsolateral processes; posterodorsal 

 and lateral spines armed with spinules, lateral 

 spines of segments 1 and 2 with relatively long 

 spinules proximally on posterior margin, seg- 

 ments with dorsal and lateral setae as figured. 

 Telson (Fig. 15e) slender with 1 pair lateral 

 spines on rounded margin and produced distally 

 into 2 long slender spines which bear 4 spinules 

 near one-third their length and tiny spinules 

 distally. 



Antennule (Fig. 2h) with peduncle unseg- 

 mented and with following armature: basal 

 lateral spine; 13-16, usually 15, long plumose 

 setae along inner, outer, and distal ventral 

 margins; smaller setae distributed near basal 



spine and along dorsal surface of peduncle in 

 clusters of 2-2-3-1-3. Flagella unsegmented; 

 outer flagellum with 3 small spines and 1 seta 

 distally, and dorsal tier of 6 aesthetascs near two- 

 thirds the length of flagellum; inner ramus very 

 small with 2 terminal spines. 



Antenna (Fig. 3f) with scale (exopod) slender 

 bearing 1 small subterminal ventral seta, 1 

 subterminal seta on outer margin, and 10 or 11, 

 usually 11, setae on distal and inner margins, all 

 setae with setules, terminal setae relatively stout 

 and graded in size from short lateral to long 

 medial seta; flagellum (endopod) with about 8 

 segments, proximal segment about the length of 

 scale, distal segment with 4 terminal spines, 1 

 seta projecting laterally from each side, and 1 

 seta directed anteriorly; a strong spine with 

 basal spinule appears on inner margin of 

 flagellum before midpoint of segment 1 and dis- 

 tally on segment 6. 



Mandibles (Fig. 4g) with 4 and 7 relatively 

 long spines on right and left blades between 

 incisor teeth and molar surfaces, bud of palp 

 present. Labrum (Fig. 4k) with anteroventral 

 spine present but shorter than in preceding 

 phase. 



Maxillule (Fig. 6d) with 11 setae on basal 

 endite. 



Maxilla (Fig. 7c) with exopod modified bear- 

 ing 1 long plumose seta on proximal lobe and 4 

 small processes approximately in position of 

 plumose setae of preceding stage; endopod un- 

 changed; medial lobes with setation of 9-5-6-6. 



First maxilliped (Fig. 8c) with form as in 

 protozoeal phase; exopod with 13 marginal 

 setae; endopod with setation of 4-3-2-5; basis with 

 13 and coxa with 8 setae. 



Second maxilliped (Fig. 9c) somewhat modi- 

 fied, long flexible exopod with 7 or 8, rarely 8, 

 setae and resembling exopod of thoracic leg 

 rather than form of preceding phase; endopod 4- 

 segmented with 3-0-2-5 setae; basis with 9 and 

 coxa with 2-4 setae. 



Third maxilliped (Fig. 12b) functional and 

 pediform; exopod with 19-23, usually 21, setae; 

 endopod 4-segmented, usually with setation of 3- 

 4-4-5, rarely with 5 setae on segment 2; basis with 

 4 setae, coxa nonsetose. 



Legs 1-5 functional; legs 1-3 (Fig. 12e) similar, 

 shorter than third maxilliped; exopods with 20- 

 22, frequently 21, setae; endopods 4-segmented 

 with 3-4-4-4 setae and bases with 3 or 4 setae. 

 Legs 4 and 5 (Fig. 16c, d) smaller than first 

 three pairs; exopods with 17-19 setae; endopods 



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