50 KECORPS OF THE AUSTHALIAN MUSEUM. 



Betropiii.ua retropitma, Waite, Mem. N.S.Wales Nat. Club, No. 2, 1904, p. 



13. LI, Zietz, Traus. Roy. Soc. S.Austr., xxxii., 1908, p. 295 (Not 



of Richardson). 

 Prototroctes semoni, Weber, Zool. Forsclir. Anstr., v., 1895, p. 274. 

 Jevynsella weatheriUi, Ogilbv, Ami. Qld. Mns., No. 9, 1908, p. 15. 

 Jenijnsella semoni, Ogilby, Mem. Qld. Mns., i., 1912, p. 32. 

 Befropinva seinoiil, Ogilby, Mem. Qld. Mns., vi., 1918, p. 97. 



Characters of a specimen of the typicnl form, 41 mm. long to the 

 end of the middle caudal I'ajs, from Ithaca Creek, near Brisbane, 

 Queensland (PI. xi., fig. 2). 



D. 2/8; A. 3/12; P. 10; V. 6; C. 18. About 54 scales in a longi- 

 tudinal row ; about 48 myomeres, the fifteenth descending to the ventrals, 

 and the twentv-ninth falling below the origin of the dorsal. Depth before 

 the vential fins 5*4 in the length to the hj-pural joint; head 4-02 in the 

 same. Eye 32 in the head : snout 1*5 in the eye, and 45 in the head. 

 Interocnlar space slightly greater than the length of the snout. Fii^st 

 branched dorsal ray 2, first branclied anal ray 1'9, pectoral 15, and 

 ventral 2'1 in the head. Mandible just closing within the upper jaw. 

 Similar in all structural details to the specimen described below. 



Description of a specimen 55 mm. long from the snout to the end of 

 the middle caudal rays, from Sackville, Hawkesbury River, New South 

 Wales, in which the anal raj's are more numerous than in the typical 

 form (PI. xi., fig. 3). 



D. 3/8; A. 4/15; P. 11; V. 6 ; C. 18. About 52 myomeres, and 

 about the same number of scale-rows between the shoulder and the 

 liypural joint. Vertebrae 50. Depth before the ventrals 6 in the length 

 to the liypural joint; head 47 in the same. Eye 3"2 in tlie head ; snout 

 1"4 in the eye, and 46 in the head. Interocuiai- space slightly greater 

 than the length of the snout. Fii'st branched dorsal and anal rays 19, 

 pectoral 1"5, and ventral 1'6 in the head. 



(leneral form moderately elongate, compressed, the dorsal and 

 ventral profiles almost evenly rounded ; the adipose membrane on tlie 

 ventral surface makes its appeai-ance between the tips of the pectorals, 

 and extends backward between the ventrals, reacliing its greatest depth 

 before the vent, where it tenuinates abruptly. Creater portion of tlie 

 body covered with concentrically striated, cjcloid scales of moderate size, 

 but these are wanting on tlie breast and anterior portion of the abdomen 

 beneath the pectoj'als; the}'' are rather irregular in theii- airangement ; 

 they extend onto the base of the caudal fin, but the remaining fins and 

 the ventral membrane are naked. No true lateral line, but the junction 

 of the angles of the myomeres is marked by a pigmented line extending 

 from the shoulder to the liypural joint beneath the scales. 



Head rather small, naked, with large open y)ores arranged regularly 

 on the nape, preoperculum, preorbital and mandihie. Snout rounded, 

 the mandible projecting slightly wIhmi the niontli is closed. Maxilla 

 broad, its obtuse point reaching backward to below the end of tlie first 



