OXYURICHTHYS 249 



Key to the Philippine and China Sea species of Oxyurichthys. 



a 1 . No tentacle present; a black spot on eye above pupil. 



6 1 . Black-margined blue ocelli on head and body; pectorals and ventrals 



with white dots O. argulus. 



6*. No blue ocelli on head or body. 

 c 1 . Scales 48 to 50 in a longitudinal series. 



d 1 . Twenty-one scales in a transverse series; no circular black spots 



on scales O. amabilis. 



<?. Fourteen to 16 scales in a transverse series; each scale on upper 



half of body with a small circular black spot O. microlepis. 



c*. Scales 75 to 80 in a longitudinal series. 



e\ Depth 7 times in length; first dorsal low, scarcely exceeding 



depth O. papuensis. 



e 1 . Depth 5 to 5.4 times in length; first dorsal high, with elongated 

 threadlike tips; 25 scales in a transverse series.... O. visayanus. 

 a*. A tentacle present on upper part of eye. 



/*. Scales 72 to 76 in a longitudinal series; tentacle very short, stout, 



teatlike O. oculo-mirus. 



/*. Scales 50 to 56 in a longitudinal series. 



g 1 . Tentacle slender, pointed, 1.6 to 3 times in eye; scales 54 to 56; 20 



to 23 before first dorsal on side of nape O. ophthalmonema. 



g*. Tentacle very short, 2.5 to 5 times in eye; scales 52; 17 to 18 before 

 first dorsal on side of nape O. viridis. 



121. OXYURICHTHYS ARGULUS (Peters) 



Gobius argulus PETERS, Monatsber. Akad. Wiss. Berlin (1868) 266. 

 Oxyurichthus argulus JORDAN and RICHARDSON, Check List Phil. Fishes 

 (1910) 50. 



Dorsal VI, 1-12; anal I, 12. 



In its whole habit, in the shape of the body, in the teeth, and in 

 the form it is extraordinarily like Gobius arabicus, but is 

 unique in the coloring of the body and head with small blue, 

 black-margined ocelli, and white-dotted pectoral and ventral 

 fins, and in the much larger scales which are in only thirteen 

 rows between the end of the second dorsal and the anal. 



On one specimen the first dorsal is dark with white longi- 

 tudinal lines, the second dorsal dark brown with a few white 

 dots and a clear margin, the anal black with numerous white 

 dots and a broad white base, the caudal uniform, dark, without 

 clear margin and unspotted. The second specimen has the first 

 dorsal as on the first specimen, the second dorsal with alternate 

 clear and dark, with oblique bands from above anteriorly to 

 below posteriorly, the anal colored as in the first example, and 

 the caudal with numerous perpendicular black crossbands. 



