NOTES AND EXHIBITS. 505 



Fresh-water Herrings, represented by a single species, the 

 "Australian Shad," Potamalosa novcB-hollandi(B (Cuvier 

 and Valenciennes), Ogilby. 



a'. Maxillaries broad, 2^ to 2-|- in the diameter of the eye. 

 Teeth entirely absent. Four branchiostegals. Dorsal inserted 

 behind the middle of the body; anal rather long, its base 

 much more than its distance from the caudal ; ventrals 

 inserted in advance of the dorsal. Scales pectinated 



HyptrJo'phus. 

 Marine Herrings, represented by a single species, the 

 "Rough-backed Sprat," Hyperloflius sprattellidei<, Ogilby. 



Dr. Cox exhibited some fine living specimens of Terehratidina 

 cancellata, Koch, attached to a stone, which he had recently 

 dredged off Forster, Cape Hawke, a new habitat which he thought 

 well worthy of record. Besides the Brachiopods, Dr. Cox stated 

 that he had also dredged the rare Trlyonia stranyei, and he 

 thought that the locality mentioned was the most northern at 

 which this rare shell had been taken. Dr. Cox also exhibited a fine 

 specimen of MyocJiama Woodsi, Petterd, from the Derwent River, 

 Tasmania. 



Professor David contributed the following note " On a remark- 

 able Radiolarian Rock" from Tamworth, N.S.W. : — "On Sep- 

 tember the 10th, in company with Mr. D. A. Porter, I obser^'ed 

 the occurrence of a remarkable radiolarian rock on the Tam- 

 worth Temporary Common. Of this rock a hand specimen and 

 section prepared for the microscope are now exhibited. The 

 section is an opaque one prepared by cementing a slice of the 

 rock about one-tenth of an inch thick on to an ordinary glass 

 slip with Canada balsam and then etching its upper surface with 

 dilute Hydrochloric Acid. The rock being partially calcareous, 

 probably an old radiolarian ooze, the lime filling in the delicately 

 latticed shells and interstices between the spines of the radiolaria 

 is dissolved out, and the siliceous shells of the radiolaria become 

 exposed to view. Some of them are exquisitely preserved for 



