242 BULLETIN 180, UNITED STATES NATIONAL MUSEUM 



OXYURICHTHYS PAPUENSIS (Valenciennes) 



Oobius papuensis Valenciennes, in Cuvier and Valenciennes, Histoire naturelle 

 des poissons, vol. 12, p. 106, 1837. 



116104, Canton Island, lagoon. May 23-25, 1939, 2 specimens. 



Genus MARS Jordan and Seale 



Mars Jordan and Seale, Bull. U. S. Bur. Fish., vol. 25, (1905), p. 408, 1906. 

 (Tjrpe, Mars strigilUceps Jordan and Seale.) 



MARS STRIGILLICEPS Jordan and Scale 



Mars StrigilUceps Jordan and Seale, Bull. U. S. Bur. Fish., vol. 25 (1905), 

 p. 408, fig. 95, 1906. 



51778 (type of Mars strigilUceps Jordan and Seale), Apia, Samoa, Jordan 

 and Kellogg. 



Genus AMBLYGOBIUS Bleeker 



AmUygolius Bleeker, Arch. Neerl. Sci. Nat., vol. 9, p. 322, 1874. (Type, 

 Qohius sphinx Valenciennes.) 



AMBLYGOBIUS PHALAENA (Valenciennes) 



OoMiis phalaena Valenciennes, in Cuvier and Valenciennes, Histoire Naturelle 

 des poissons, vol. 12, p. 92, 1837. 



116106, Canton Island, lagoon. May 25-26, 1939, 29 specimens. 

 116108, Canton Island, lagoon, May 23-25, 1939, 12 specimens. 



116107, Canton Island, lagoon, April 23 to May 12, 1939, 3 specimens. 



116105, Canton Island, lagoon. May 25-26, 1939, 1 specimen without vertical 

 color bars may be a new form. 



51815, Apia, Samoa, Jordan and Kellogg, 4 specimens. 



Genus OPLOPOMUS Ehrenberg 



Oplopomus (Ehrenberg) Cxjvier and Valenciennes, Histoire naturelle des pois- 

 sons, vol. 12, p. 66, 1837. [Type, Oplopomus pulcher Ehrenberg {=Oobiug 

 oplopomus Cuvier and Valenciennes).] 



OPLOPOMUS DIACANTHUS, new species 



Figure 21 



Holotype. — The only known specimen (U.S.N.M. No. 116116), 

 34.3 mm. in standard length, collected by Leonard P. Schultz in the 

 lagoon of Canton Island, May 25-26, 1939. 



Description. — (Based on the holotype. All measurements are 

 recorded in hundredths of the standard length.) Length of head 

 24.8; greatest depth 16.3; diameter of eye 6.7; distance from tip of 

 snout to rear edge of maxillaries 7.6 ; length of snout 7.6 ; postorbital 

 length of head 12.0; least width of preorbital 3.8; length of caudal 

 peduncle 22.5; least depth of caudal peduncle 8.5; tip of snout to 

 origin of dorsal fin 33.6; snout to origin of anal fin 53.0; snout to 



