454 NOTES ON PROSOBRANCHIATA, 



Australian Fossil Species. 



That their relationships are to recent species occurring only in 

 southern waters is one of the facts which strike the student of 

 Australian fossil Lotoriid^. L. quoyi, Reeve, exists fossil as well 

 as recent. L. philomelce is so like L. oligostirum, Tate, that it might 

 be as aptly termed a "living fossil" as Trigonia. Other recent 

 allies of these are L. verrucosum, ehurneuin, and nodocostatum from 

 Southern Australia. L. parkinsonianu7)i is the recent represen- 

 tative of L. radiale, abbotti, textile, woodsi, and tortirostris. This 

 group is more distinct than any I have studied. L. tortirostris 

 bears a resemblance to L. waterliousei; but, to institute a com- 

 parison, this resemblance is not so great as that existing between 

 L. subdistortum and bassi. A s already stated, if it is advantageous 

 to name the groups. Septa must be reserved for this one. The 

 species tumulosum is nearly allied to subdistortum, whilst bassi is 

 represented hj ovoideum, and an undetermined species intermediate 

 between them. Lotorium jjrotensum is possibly an archaic form, 

 and resembles somewhat the Fusid^e from which the genus is 

 apparently descended. Lotorium cyphus seems to stand alone; 

 it might be considered as shadowing forth Distortio, and bears a 

 striking resemblance to Cassidaria gradrata, Tate (35, 169); this 

 resemblance is, however, dispelled on comparing young specimens. 

 The existence of such widely different species as protensum and 

 cyphus in an early Tertiary stratum points to a much earlier 

 horizon for the genus than the text-books admit; the wide dis- 

 tribution of the genus in Tertiary times is also evidence of this. 



The parkinsonianum-grouip is of particular interest from a| 

 zoogeographic and palseontological point of view. The type is toj 

 be regarded as the only surviving species of an otherwise extinct 

 Antarctic group). There are in Southern Australian beds six 01 

 nine species; in Patagonian beds one {L. bicegoi); and the New^ 

 Zealand Tertiary species, L. minimum, is probably referable here 

 also. We have here, then, another link in the already strong 

 chain of faunal relationship shown to exist between these three 

 countries. 



