FISHES OF THE PHILIPPINE SEAS AND ADJACENT WATERS 227 



to replace Gerres (Cuvier) Quoy and Gaimard, thought preoccupied by 

 Gerris Fabricius.) 



Catochaenum Cantor, Journ. Asiat. Soc. Bengal, vol. 18, No. 1, p. 1037, 1849(1850). 

 (Type, Gerres vaigiensis (Cuvier) Quoy and Gaimard, virtually, as Cato- 

 chaenum Cantor proposed to replace Gerres (Cuvier) Quoy and Gaimard.) 



Synistius Gill, Proc. Acad. Nat. Sci. Philadelphia, 1862, p. 238. (Type, Gerres 

 longirostris (Rapp) Gunther= Xysiaema rappi Barnard, monotypic.) 



Xystaema Jordan and Evermann, Proc. California Acad. Sci., ser. 2, vol. 5, p. 

 471, 1895. (Type, Mugil cinereiis Walbaum, monotypic.) 



Pertica Fowler, Journ. Acad. Nat. Sci. Philadelphia, ser. 2, vol. 12 p. 530, 1904. 

 (Type, Gerres filamentosus Cuvier, orthotypic.) 



Parochusus Whitley, Mem. Queensland Mus., vol. 10, pt. 1, p. 16, 1930. 

 (Type, Gerres profundus Macleay, orthotypic.) 



Body elevated, oblong ovate. Eyes large. Mouth extremely pro- 

 tractile, extends down as protracted. Preopercle entire. Air bladder 

 simple. Pyloric coeca few, 3 or 4. Branchiostegals 6. Scales mod- 

 erate, cycloid or finely ctenoid. Dorsals equal, spines 9, rays 10 or 11 

 and front spines more or less elevated. Anal spines 3, rays 7 to 9. 

 Caudal forked. Pectoral usually long and falcate. 



"The species comprising this genus are somewhat difficult of de- 

 termination unless a good collection is brought together, but even 

 then some important considerations have to be borne in mind prior 

 to deciding whether the specimen belongs to a known or an unknown 

 species. The eye, certainly in some, increases in comparative size 

 with the head as age advances, as occurs in Megalops cyprinoides, 

 etc. The first dorsal spines may be compressed or rounded; and the 

 second and third slightly or very elongate, but this elongation often 

 varies considerably, as seen in G. filamentosus, in which it may be 

 only two-thirds the height of the body or even extending as far as the 

 base of the caudal fin, and though this difl'erence is generally, it is not 

 always, due to age, but in the young it is mostly shorter than in the 

 adult. Even in the anal spines the second may be equal in length to 

 the third or a little longer or shorter in the same species. As regards 

 colour the young are generally vertically banded, and these bands may 

 be indistinct or even entirely absent in the adult. In those with 

 longitudinal bands they sometimes become interrupted in large 

 specimens, showing rows of long oval blotches or marked one over 

 the other, the reason usually being that these marks are apparent in 

 the adult where the vertical bands existed in the immature." (Day.) 



Gerres australis Castelnau 



Gerres australis Castelnau, Off. Rec. Philadelphia Exhib. (Victoria), Res. 

 Fish. Australia, p. 43, 1875 (type locality: Swan River, West Australia). — 

 Macleay, Proc. Linn. Soc. New South Wales, vol. 5, p. 377, 1881 (compiled). 



Depth 2}^, head 3. Snout equals eye. Second dorsal spine thick, 

 long, half length of body, third nearly as long, but slender. Second 

 anal spine stronger but shorter than third. Silvery, upper parts 

 purple. Soft dorsal with a line of faint obscure spots. An appear- 



