231 



X. subauriculata and L. elUptica differ from L. Jeffreysiana 

 by their ribs, smooth sides, medial furrows, and more inflated 

 umbos. Among recent Australian shells the fossil species 

 approaches L. Strangei, from which it differs by its straighter 

 sides, by its more numerous and acute ribs, and by being more 

 ventricose. 



The majority of the new species have considerable analogy 

 with recent congeners ; but especial interest attaches to the 

 existence in a fossil state of the genus Chamostrea, hitherto 

 represented by a single species proper to South-eastern and 

 Southern Australia and to Tasmania. The presence of 

 Potamides is also noteworthy ; one of the fossil species is 

 much larger than any known recent form. A few Table 

 Cape species, in my liands, await elaboration ; but as it is 

 imperative that the fossils should be studied in comparison 

 with living forms, it is obvious, unless the necessary 

 material be readily available, that an immediate and satis- 

 factory answer cannot be given to the question : — Which of 

 them are now known to be living, and which of them are 

 supposed to be extinct ? 



I shall be happy to work out any material, that the Society 

 or other possessors of Table Cape fossils may entrust to me, 

 and I may add that my very rich collection of tertiary fossils 

 enables me to institute a comparison of the Tasmanian fossils 

 with those from continental and other localities. 



DESCEIPTION OF A NEW SPECIES OF ODAX. 



By Eobt. M. Johnston, F.L.S., Etc. 



[Bead July 7, 1884.] 



The following is a description of a new species of Odax, 

 caught in the waters of the Derwent, and presented to me by 

 Captain Beddome. 



Odax Beddomei (Nov. sp.). 



Df§, Af, P12-14. 

 L. lat. 40. L. tr. ^y. 



Body elongate. Praeoperculum entire. Snout much pro- 

 duced and finely pointed. Eye rather large. Height of body 

 one-tenth of the total length, and length of head contained 

 in the latter three and one-third times. Upper posterior 

 margin of operculum produced into a flaccid membrane 

 having a rayed appearance. Colour of body and fins reddish, 

 becoming lighter below lateral line. There is a singular well 



