188 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 115 



Remarks. — This genus is very similar to Lepeophtheirus. The 

 ten species known for the genus, including the new species described 

 in this pubhcation, possess only one characteristic in common: the 

 rudimentary abdomen, and even this is not unique, A. renalis Hee- 

 gaard having a distinct abdomen as does the male of ^. serratus Shiino, 

 here described for the first time. As Shiino (1954) indicates, all of 

 the species possess characteristics in common with other members of 

 the genus but not in common with all of the members. 



Anuretes serratus Shiino 



Figures ISa-n, 14o-/ 

 A. serratus Shiino, 1954e, pp. 260-264, figs. 1-2. 



Distribution. — Japan, Hawaii. 



Hosts. — Xesurus scalprum (Cuvier and Valenciennes), Naso 

 hexacanthus (Bleeker). 



Material. — Male and ovigerous female (USNM 105097) collected 

 by author from caudal fin of two specimens of Naso hexacanthus 

 (Bleeker) taken in fish traps between Diamond Head and Koko Head, 

 Oahu, Hawaii, by Samuel Kaolulo. Two specimens selected from 

 collection of over 100 specimens to exemplify Hawaiian population 

 of species. 



Measurements. — Female: Length from anterior end of body to 

 posterior end of caudal rami, excluding setae, 2,48 mm. Greatest 

 length of cephalothorax, including frontal region, 1,85 mm.; greatest 

 width, excluding marginal flanges, 1.56 mm. Greatest length of 

 genital segment and fused abdomen 0.50 mm. ; greatest width of genital 

 segment 0.82 mm. 



Male: Length from anterior end of body to posterior end of caudal 

 rami, excluding setae, 1.64 mm. Greatest length of cephalothorax, 

 including frontal region, 1.29 mm.; gi'eatest width, excluding marginal 

 flanges, 0.84 mm. Greatest length of genital segment and abdomen 

 0,45 mm,; greatest width of genital segment 0.48 mm. 



Description. — Body of male and female opaque in alcohol, with 

 rows of red pigment spots concentrated in posterior portion of cephalo- 

 thorax and genital segment. Eyes orange-red. 



Cephalothorax of female oblong, slightly longer than wide; frontal 

 region distinct, anterior margin indistinctly crenate. Frontal region 

 set off from cephalothorax by distinct, trilobed groove, median lobe 

 much larger than lateral lobes. Lateral margins of cephalothorax 

 with narrow marginal flange. Posterior sinuses distinct, deep, wider 

 at apex than at opening, with membranous flange around most of 

 margin. Flange not mentioned by Shiino (1954) in original descrip- 

 tion but present in both female and male specimens. Median cephalo- 

 thoracic area extending posteriorly slightly past posterior extensions 



