HAWAnAN ACANTHURID CALIGOIDS — LEWIS 215 



Lateral margins of thii'd thoracic leg-bearing segment concave in 

 anterior portion of older specimen, convex in posterior portion, curving 

 sharply inward to junction of fourth thoracic leg-bearing segment. 

 Greatest width of third thoracic leg-bearing segment in older specimen 

 slightly more than twice length. Lateral margins of fourth thoracic 

 leg-bearing segment of younger specimen broadly rounded, greatest 

 width slightly less than twice greatest length. Fourth thoracic leg- 

 bearing segment in older specimen ovoid, greatest length about tlu-ee- 

 fourths greatest width. 



Width of genital segment in early encysted specimens slightly less 

 than width of fourth thoracic leg-bearing segment. Lateral margins 

 broadly rounded in anterior three-fourths of segment in younger speci- 

 men, curving sharply inward posteriorly to slight projection of medial 

 two-thirds of segment; greatest length about two-thirds greatest width. 

 Lateral margins of segment in older specimen flatly convex, greatest 

 length slightly more than two-thirds greatest width. Abdomen short, 

 one-segmented; slightly longer in older than in younger specimen. 

 Greatest length of abdomen approxmiately half length of genital 

 segment (figs. 20a,b). 



Cephalothorax of late encysted and recently excysted forms ovoid. 

 Frontal region distinct, narrow, anterior margin flatly rounded; 

 frontal region with distinct transverse ridges across entire surface 

 though not as distinct on posterior as on anterior surface. Division 

 between frontal region and cephalothorax distinct, complete; small 

 projecting lobe in middle of margin separating frontal plates in ex- 

 cysted specimen present but not reaching anterior margin in late 

 encysted specimens, though plates separated by distinct groove 

 extending from anterior projecting lobe to anterior margin. Lateral 

 margins of cephalothorax with very thin flange on anterior portion, 

 broader on posterior portion, extending around posterior extensions 

 of lateral regions into posterior sinuses. Posterior sinuses distinct, 

 slender, V-shaped. Posterior sinuses extending anteriorly to junction 

 of cephalothorax and second thoracic leg-bearing segment; posterior 

 extensions of lateral cephalothoracic regions projecting to middle of 

 second thoracic leg-bearing segment. Median posterior marginslightly 

 irregular, extending between apices of posterior sinuses. Longitudinal 

 grooves on dorsal surface of cephalothorax distinct posteriorly, ex- 

 tending from apex of posterior sinuses anteriorly, becoming indistinct 

 lateral and posterior to eyes though discontinuous extensions visible 

 curving anteriorly and laterally, extending to proximity of lateral 

 margin. Indistinct, discontinuous median longitudinal groove pres- 

 ent, extending posteriorly to anus from V-shaped, indistinct groove 

 posterior to eyes. Eyes distinct, consisting of pair of oval eyes, one 

 on either side of median longitudinal axis of body, with inner margins 



