232 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 115 



Bassett-Smith (1899) and Wilson (1922), without seeing the holotype 

 and only specimen, placed the genus Norton with the Caligoida. 



Nordmann (1864) indicates that he found no evidence of body 

 segmentation other than the presence of appendages in the cephalo- 

 thorax. This was probably due to the covering of the posterior 

 portion of the body by the single dorsal and paired ventral plates. 

 With sufficient material at hand, this author has been able to examine 

 members of the species in greater detail than did the original author. 



The segmentation present in the specimens collected, the distinct 

 segmentation of the antennule, the presence of four pairs of thoracic 

 legs, and the presence of uniseriate egg strings indicate that this 

 genus, represented solely by A^. expansus, belongs in the Caligoida, 

 not the Cj^clopoida. The fusion of the first thoracic leg-bearing 

 segment, the maxilliped-bearing segment, and the cephalon, in 

 addition to the presence of dorsal plates, indicates that the species is 

 a member of the family Anthosomatidae. The similarities of the 

 single dorsal plate covering the posterior surface of the animal and 

 the paired ventral plates found in A^. expansus to those of some mem- 

 bers of the genus Sagum, S. angulatum (Kr0yer), and those of some 

 members of the genus Lernanthropus, L. pagelli Kr0yer and L. chryso- 

 phrys Shishido, indicate a distinct relationship between these genera. 

 In addition, the maxilla of N. expansus, especially the distal end and 

 terminal process of the second segment, is similar to that of members 

 of the genus Lernanthropus, and the laminate third thoracic leg of 

 N. expansus is similar to the fourth leg of species of the genus Sagum. 



This parasite is comparatively rare in the Hawaiian Islands; the 

 author collected three from 189 specimens of Naso, the only genus 

 upon which the parasite was found. The additional two specimens 

 were collected by Dr. Hilda Ching from a single, large specimen of an 

 unknown species of Naso. 



Family Lernaeoceridae 



Genus Peniculus Nordmann, 1832 



Diagnosis. — Female: Body elongate; head without horns but 

 lateral lobes may be present; separated from posterior body by neck 

 consisting of thoracic leg-bearing segments 1-3 or segments 2 and 3, 

 one being fused with cephalon in the latter. Fourth thoracic leg- 

 bearing segment swollen, either separated from fused genital segment 

 and abdomen by constriction or fused with these segments. Antennule 

 reduced or absent; second antenna forming organ of attachment, 

 terminal process clawlike, distinct in immature specimens, indistinct 

 in mature. Mouth cone retractible; cephalic appendages consist of 

 second antennae, mandibles, maxillae, and maxillipeds, Thoracic 



