HAWAIIAN ACANTHURID CALIGOIDS — LEWIS 



141 



prot1 



s P 



Figure 1. — Hypothetical thoracic leg showing various armament components: 

 C: heavy fringing setules P': large naked seta 



p: smaller plumose seta 



c: light fringing setules 

 d: denticulations 

 dH: denticulated spine 

 endo: endopodite 

 exo: exopodite 

 f: membrane 

 H: simple spine 

 H': hooked spine 

 P: large plumose seta 



p': smaller naked seta 



prot: protopodite 



Q: seta plumose on one side with membrane 



on other 

 rh: spinule 



s: solitary hairlike setule 

 sp: sternal plate 

 numbers: segment numbers 



Family Caligidae 

 Genus Caligus Miiller, 1785 



Diagnosis. — First three thoracic leg-bearing segments fused with 

 head to form cephalothorax, fourth thoracic leg-bearing segment 

 free, without paired dorsal plates; genital segment without plates or 

 processes; abdomen of one or more segments. Frontal plates with 

 lunules; sternal furca present; first three thoracic leg pairs bu'amous 

 though endopodite of first pair rudimentary in the adult; fourth 

 thoracic legs uniramous. 



Remarks. — The diagnosis presented above was modified from 

 Wilson (1905). The second maxillae described by Wilson as simple 

 and spinelike are, in the present work, the postoral processes which, 

 in species such as Caligus constrictus, may be bifurcate. The first 

 thoracic leg is described here, in opposition to previous workers, as 

 biramous. The presence of an endopodite in the adult and in the 

 developmental stages, whether rudimentary or not, indicates that 



