HAWAIIAN ACANTHURID CALIGOIDS — LEWIS 211 



The name "bifurcatus" applies to the bifurcate condition of the 

 postoral process and of the third thoracic leg exopodite process. 



Family Pandaridae 



Genus Nesippus Heller, 1865 



Diagnosis. — Cephalothorax consisting of cephalon, maxilliped, and 

 first thoracic leg-bearing segments; second, third, and fourth thoracic 

 leg-bearing segments free. Cephalothorax typically longer than wide, 

 with posteriorly projecting lateral regions. Male with or without 

 conspicilla placed slightly anterior and lateral to paired eyes. Sec- 

 ond thoracic leg-bearing segment with lateral and posterior lateral 

 projecting lobes. Abdomen small, one-segmented. Distal region of 

 maxillipeds swollen, terminal process knoblike, forceps-like or 

 flattened and clawlike. All thoracic legs biramous; rami of legs 1-3 

 two-segmented, fourth leg rami one-segmented. 



Remarks. — The diagnosis is mainly from Wilson (1907) with modi- 

 fication based on the characteristics of the species described subse- 

 quent to his publication. The adult female and male of this genus 

 are found primarily on elasmobranch hosts, but the adult male also 

 is taken in the plankton. 



The function of the "conspicilla," Dana's term for the two trans- 

 parent projections on the dorsal surface in the region of the eyes of 

 some males, is not known. Dana (1853) indicates that they are dis- 

 tinct from the cephalothorax and are of a "brittle, though rather hard" 

 nature. 



Nesippus costatus? Wilson 



Figures 19a-e, 20a-s, 21a-p 

 N. costatus Wilson, 1924, pp. 213-214, pi. 20. 



Type host. — "A nine-foot shark." 



Type locality. — Galapagos Islands. 



Material. — Immature male taken by author from cyst on dorsal 

 fin of specimen of Acanthurus triostegus sandvicensis Streets captured 

 by U.S. Fish and Wildlife Service, Bureau of Commercial Fisheries, 

 at Midway Island (USNM 105176). Immature male taken by author 

 from cyst on anal fin of specimen of Acanthurus nigroris Cuvier and 

 Valenciennes captured in fish trap in Kaneohe Bay, Oahu, Hawaii, 

 by Lester Zukeran (USNM 105177). Immature male from cyst on 

 anal fin of specimen of Acanthurus xanthopterus Cuvier and Valen- 

 ciennes captured in fish trap in Kaneohe Bay, Oahu, Hawaii, by 

 Lester Zukeran (USNM 105178). Male specimen collected by Dr. 

 John Randall from epidermis of specimen of Acanthurus triostegus 

 sandvicensis Streets from an unknown locality, probably on Oahu, 



