290 RECORDS OF THE AUSTRALIAN MUSEUM. 



Depth at ventral fins 3'8-4"3 in the length to the hypural joint ; 

 head Si-SQ in the same. Eye 3"4-38 in the head, subequal to or slightly 

 narrower than the interocular space. Snont 1"1-1'2 in the eye. Depth 

 of the caudal peduncle 2-7 in the head ; its length from the last dorsal 

 ray to the hypural joint is slightly shorter than the head in the male, 

 and a little longer than it in the female. 



Cheeks with rudimentary scales, operculum scaly. Numerous rows 

 of minute pores are present on the cheek, operculum and snout, and 

 surrounding the eye, preoperculum_ and mandible; no larger pores. Eye 

 of moderate size, a little longer than the snout. Nostrils large, simple 

 openings, the anterior near the lip, the posterior near the orbital margin. 

 Teeth microscopic, villiform, in a band in each jaw. Tongue rounded 

 anteriorly. Gill-openings wide, the space between the membranes about 

 as wide as the e3"e. Inner margin of the shoulder-girdle smooth. 



Body moderately compressed, covered with ctenoid scales, which 

 extend forward to behind the eye, onto the base of the pectoral fin, and 

 the thorax ; they are small and irregular on the nape, but become larger 

 backwards. Genital papilla large in both sexes. Vertebrae 31, including 

 the hypural. 



First dorsal originating well behind the pectorals and ventrals ; its 

 spines are low, and its margin rounded. Second dorsal higher than the 

 first, j)ointed posteriorly in the male, rounded in the female. Anal 

 similar to the second dorsal. Pectoral rounded, not reaching the vertical 

 of the vent. Ventral inserted just behind the pectoral, pointed, the 

 penultimate ray longest, not reaching the vent. Caudal rounded. 



Colour -marking. — General colour greenish brown in formaline, the 

 scales of the back and sides with darker margins. A characteristic row 

 of dark vertical bars at the base of each scale along the middle of the 

 side, and a blackish axillary spot. Head dusky with microscopic dots. 

 Dorsal and anal fins dusky in the male with white margins and a darker 

 submarginal stripe ; caudal dusky, ventials and pectorals transparent. 

 The fins of the female may be similar to those of the male or quite 

 transparent. 



Described from twelve specimens 29-56 mm. long, including six 

 males and six females, which were captured together in the Cudgegong 

 River at Ryleston by Mr. D. G. Stead, l8th December, 1911. They 

 exhibit remarkable Sexual Dimorpliishi which is figured on Plate xxxvii. 

 The adult male has the nape, occiput, and interorbita! area greatly swollen, 

 the upper profile of the head being so elevated that the eye is far removed 

 from it ; the posterior rays of the dorsal and anal fins are longer than 

 those preceding them, and the caudal peduncle is shorter than in the 

 female. The eye of the female is close to the profile of the head, the 

 interorbital space being only slightly convex ; the dorsal and anal fins are 

 rounded, the thii-d or fourth rays being longest, and the caudal peduncle 

 is long and slender. 



Variation. — Several series of specimens from various localities between 

 Narrandera, on the Murrumbidgee River, New South Wales, and Eidsvold, 

 on the Burnett River, Queensland, prove that this species varies 

 considerably in the number of spines and rays in the dorsal and anal fins, 

 and in its scale counts. But the fact that sotne examples from the two 



