86 



On Some Regent and Fossil Australasian^ 

 Species of Philobry^e. 



By Professor Ralph Tate. 

 [Read August 2, 1898.] 



Plate IY., Figures 8-10. 



The bivalved mollusca, which constitute the genus Philohry(^ 

 are minute shells, which present in their adult state various 

 characters proper to the very young states of Mytilidcey 

 Aviculidm^ and Arcidee. They were little known to malacologists 

 till the appearance last year of M. Felix Bernard's " Etudes 

 comparatives sur les genres Philohrya et Hochstetteria.^^ Bernard 

 has provisionally placed these two genera as a subfamily 

 {^PhilobryincB ) in the family AviculidcB ; but the absence of 

 prismatic structure of the test, and the existence of a copious 

 periostracum incline me to the opinion that the systematic 

 position of this subfamily is rather with Mytilidce than with 

 AviculidcB. 



Of the eleven species referred by Mr. Bernard to this 

 subfamily, nine occur in the Southern Hemisphere, chiefly in 

 moderately high latitudes. The recognition of the existence of 

 Philohrya in Australian waters is, therefore, not unexpected ; but 

 greater interest is attached to the fossil record, here announced for 

 the first time, as may be gathered from the following extract from 

 M. Bernard's essay : — " II est indispensable de rechercher si 

 parmi les formes fossiles il n'en existe aucune qui pourrait soit 

 rentrer dans le genre Philohrya, soit s'en rapprocher plus que ne 

 font les Anisomyaires actuels. Je n'ai trouve aucune indication 

 de cette nature en ce qui concerne les faunes secondaire et 

 tertiare. La cause en est peut-etre dans la petitesse de ces 

 coquilles qui peuvent avoir echappe aux investigations, ou bien 

 avoir ete considerees par ceux qui les ont recueillips comme des 

 jeunes ou de petites especes d'Aviculides, de Mytilides ou 

 meme de Lima. Les fossiles primaires m'ont fourni quelques 

 indications qui, tout en manquant pour le moment de precision, 

 me paraissent devoir soulever une utile discussion." Journ. de 

 Conch., No. 1, 1897, p. 41. 



The additional species — subjects of the following records are : 

 — Two living in Southern Australia and Tasmania, one from the 

 Newer Tertiary of New Zealand, and two from the Older Tertiary 

 of Victoria. 



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