26 RECORDS OF THE ATTSTRALIAN MUSEUM. 



forces upon us the consideration whether these characters, taken 

 separately or in conjunction, should not entitle this and similar 

 forms to generic rank. The latter character, however, that is the 

 acute spiniferous ridge between the occiput and the dorsal fin, is 

 common to all the fresh- water and estuary non-migratory Herrings 

 of the cismontane rivers of the Colony, between the limits of the 

 Richmond River and Botany Bay, which the author has had an 

 opportunity of examining : the former character, that of the 

 position of the ventral fin, has been extensively used by 

 systematists as one on which to base a separate genus. This is 

 not the place to discuss the importance or otherwise of this 

 character, but it is worthy of notice that in our common fresh- 

 water herring [Clupea novce-hollandice, Cuv. & Val. = C. rich- 

 mondia, Macl. = (?) C. vittata, Casteln.) the ventral fins are 

 inserted immediately below the origin of the dorsal. 



With regard to the dorsal serrature, we appeal to our fellow- 

 workers in other countries to examine more carefully the anadro- 

 mous herrings of their rivers and estuaries, for should it prove to 

 be the case that all the fresh-water herrings have this character- 

 istic, they are clearly separable from the typical Clupea. 



All species, therefore, in which the occipito-dorsal serrature 

 is present, might be separated therefrom under the name of 

 Hyjierlophus, and distinguished from Cluj^ea by this character. 



On the structure and AFFINITIES op PANDA 



ATOM AT A, Gratj* 



By C. Hedley, F.L.S. 



[Plates IV. V. VI.] 



Some uncertainty appears to prevail regarding the position which 

 Bulimus atomatus, Gray, should occupy. The latest volume of 

 the "Monographia HeliceorumViventium" includes it in a section 

 embracing another Australian and a dozen South American 

 species, an arrangement which must surely violate natural 



*Since this essay was written I learn that, by an odd coincidence, both 

 Mr. Pilsbry and myself independently arrived at the conclusion that 

 atomnta should correctly be referred to Panda, and published our opinions 

 simultaneously in America and Australia, in "The Nautilus," Vol. VI., 

 No. 1, p. 9, May, 1892; and in the "Abstract" of the Proceedings of the 

 Linn. See, N.S.W., April, 1892, respectively. 



