BHINOGOBIUS 177 



acter is common to many species of Rhinogobius and presents 

 every stage of development, from those with none or with only 

 one or two lines across the cheeks, up to those with an exten- 

 sive and elaborate system of crisscross lines over the sides of 

 the head, so that at no place am I able to make a hard and fast 

 distinction. Species with or without a scaled nape, with more 

 or fewer scales and fin rays, may have the same complicated 

 system of lines on the cheeks or may have them equally smooth ; 

 the presence or absence of these papillae does not link with any 

 other character. From the other species of Rhinogobius one 

 might separate Drombus palackyi and Drombus viridi-punctatus 

 by the dentition, but there hardly seems enough difference to 

 warrant the segregation. 



I regard Rhinogobius as treated here and by other authors as 

 very unsatisfactory; probably many of the species should go to 

 Ctenogobius, of which Rhinogobius is probably a synonym, and 

 the rest should be distributed into new genera. 



A genus of general distribution. 



Key to the Philippine and China Sea species of Rhinogobius. 

 SECTION DROMBUS 



a 1 . Nape scaled to eyes. 



6 1 . Teeth in six to nine rows in each jaw. 

 c 1 . Thirty-one lateral scales; 18 or 19 before first dorsal, not extending 



to eyes-. R. palackyi. 



c 1 . Thirty-four to 38 lateral scales; 30 to 32 before first dorsal, extend- 

 ing to eyes R. viridi-punctatus. 



SECTION RHINOGOBIUS 



b*. Teeth in three to five rows in each jaw. 

 d 1 . Not more than 10 scales before first dorsal. 

 e 1 . Lower jaw inferior. 



f. Scales before first dorsal 6 to 8; in lateral series 26 to 28; 

 second dorsal 1-8; anal 1-8; six longitudinal brown lines; 

 five large black spots along middle of side; eight large brown 

 spots between fifth and sixth lines; a black ocellus between 



first and second dorsal spines R. decoratus. 



f. Scales before first dorsal 9; in lateral series 26; second dorsal 

 1-10; anal 1-9; sides with several longitudinal dusky bands 

 and rows of black spots; no black ocellus on first dorsal. 



R. calderae. 



e 1 . Jaws equal; scales before first dorsal 10; in lateral series 25; 

 second dorsal 1-11 ; anal I, 10 ; color brown, with about fourteen 

 small circles of darker brown along middle of sides. 



R. hongkongensis. 

 d*. Scales before first dorsal 15 or more; lower jaw projecting. 



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