170 ' MEMOIJi'S OF THE QUEENSLAND MFSELM. 



Genus DAYA Bleeker. 



DayaBleekcv, Verb. Holl. :\Iij. Haarlem. 1877. p. 71 [Pomacentrus jerdoni Day). Id. Weber, 

 Siboga Fifche, Ivii. 101. "K p. 343. 



This gonus differs from l'i)mac( ntrus in havino; no scaly slieaths at the 

 hase.s of the spinous dcrsal and anal fins, and the membrane between the spines 

 naked instead of scaly. The edges of the suboperculuiii and interopereulum are 

 finely serrated like the preopereulum, and the sul)orl)ital l)ones are small and 

 ineonspieuoiLs ; opereulum with two spines. The anterior teeth of eaeh jaw are 

 enlarged, and, though ecmpressed, have more or les-^ rounded points; the lateral 

 teeth small. Snout and mandibl-^ naked. Caudal fin forked. Scales in about 

 thirty rows. Membrane of spinous dorsal scarcely incised and without distinct 

 lobes. 



DAYA JERDONI Day. 



(Plate IX, fig. ].) 

 Ponmcentrus jerdoni Day. Proc. Zool. Soc. Lond. 1873. p. 237; and Fissh. India. 1877, p. 383- 



pi. Ixxx, fig. 7. 

 Daya jerdoni Weber, Fische Siboga Exped., Ivii, 1913, \i 344. 

 Pomacentrus dolii Macleay, Proc. Linn. Soc. N.S. Wales vi. 1881, p. 65, pl. i, fig. 1. 



D. xiii/13 ; A. ii/14 ; P. 18 ; V. i/5 ; C. 15 ; L. lat. 19 ; 30 scales between the 

 origin of the lateral line and the hypural joint, 5 bet^veen the origin of the 

 dorsal and the lateral line, and 10 more to the origin of the anal. 



Depth before the yentraLs 2-6 in the length to the hypural joint ; head 3-5 

 in the same. Eye 34 in the head and a little longer than the snout, Avhich is 

 4-2 in the head; interorbital width a little greater than the length of the eye, 

 3-1 in the head. Sixth dorsal spine 2-1 in the head, longer than the last, but 

 much shorter than Ihe ninth ray; pectoral 1-2 in the head. 



liody longer than is usual in Pomacentrids, with the upper and lower 

 profiles equally curved from the obtusely conical snout. Suborbital bones small 

 and inconspicuous, the first wider than the others and hinged with the preorbital; 

 free edge of the preorbital notched and feebly serrated. Hinder edge of the 

 preopereulum serrated, as is that of the suboperculum, and the interopereulum 

 also has a few serrations. Opereulum armed with two fiat spinas, the lower of 

 which is the larger. Each jaw with about six large flattened teeth in a row 

 anteriorly, and a row of much smaller ones on each side ; palate toothless. 

 Nostril a simple opening on eaeh side. 



Scales ctenoid with narrow ciliated borders. They extend forward on the 

 upper surface of the head to before the middle of tbs eye, and cover the whole 

 head Mith the exception of the snout, lips, and mandible. There is an enlarged 

 scale at the base of each ventral fin, and two others are present between those 

 fins. Scales cover the bases of the pectoral fins, and extend up between the 

 dorsal, anal, and caudal rays, but the spinous portions of the dorsal and anal 

 are naked. Lateral line formed by a broad canal, with two or three poras 

 opening on each scale; the scales of the median series on the caudal peduncle 

 also bear minute pores. 



