HAWAIIAN ACANTHURID CALIGOIDS — LEWIS 



177 



Fourth thoracic leg unu*amous, three-segmented. Protopodite one- 

 segmented, sHghtly longer than combined length of two segments of 

 expedite. Protopodite slender, with two hairlike setules from outer 

 sm-face, one in proximal region, second in distal region; single, small, 

 plumose seta present on outer distal corner. Greatest length of first 

 exopodite segment slightly less than that of second; with single, 

 elongate spine from distal surface. Second segment of exopodite with 

 three spines on flat distal surface, inner spine longest, outer shortest. 

 All four spines on two segments of exopodite with fine membrane along 

 inner and outer margins; three terminal spines, on second segment, 

 with frilled membrane around base (fig. lOg). 



The character of the membranes, spines, and setae on the thoracic 

 legs is given below (for explanation of symbols, see figure 1): 



Width of caudal ramus greater than length, greatest length approx- 

 imately two-thirds length of abdomen; inner margin setuliferous. 

 Six plumose setae present on distal margin, one short seta from inner 

 corner, two short setae from outer corner, three long setae from middle 

 of posterior margin (fig. 106). 



Remaeks. — The fusion of the fourth thoracic leg-bearing segment, 

 genital segment, and abdomen of C. kalumai is found in several 

 members of the genus Caligus. In general characteristics C. kalumai 

 most closely resembles C. oviceps Shiino, 1952, and C. punctatus 

 Shiino, 1955 ; it differs from C. oviceps by the presence of three segments 

 in the fourth thoracic leg instead of four, the nature of the terminal 

 processes on the first thoracic leg, the presence of two naked spines 

 on the third segment of the exopodite of the second thoracic leg 

 instead of the single plumose spine noted by Shiino for C. oviceps, 

 and by other characteristics. C. punctatus and C. kalumai difter 

 primarily in the characteristics of the first and fourth thoracic legs, 

 C. punctatus with short, stift' terminal processes on the first leg, in 

 contrast to the longer, more flexible processes of O. kalumai; they 



