318 RBCORDS OF THE AUSTRALIAN MUSEUM. 



His description of the operculum and dentition was dismissed by 

 Tryon with the remark that the species had not the pearly nacre 

 of a Trochus} 



The dentition of F. patula is shown in Fig. 28 (a), as also the 

 rachidian of F. petterdi (b), which seems to differ from that of the 

 former in having an expanded root, but this difference probably 

 does not really exist, for it was only seen with great difficulty, 

 owing to its transparency, in a dismembered ribbon, and it is 

 likely that it exists, unseen, in F. patula also; there is no other 

 difference between the two ribbons. The opercula of both species 

 are so typically trochoid, that it has not been thought necessary 

 to figure them; the form also of the shells is congeneric, and it 

 was on a supposed anatomical difference that Button separated 



them. The careless- 

 ness of the authors of 

 Fossarina has led to 

 the making of the 

 genus Minos. The ne- 

 cessity for Part II. of 

 this paper is another 

 result of that careless- 

 ness. That the shell 

 which I have regarded 

 as F. patula, is cor- 

 rectly identified there 

 can be no doubt. It 

 agrees perfectly with 

 the description and figures, with the exception of the operculum; 

 moreover it is the shell which has been so identified by every local 

 Conchologist, including Messrs. Hedley and Brazier. 



Tate and May, in dealing with the genus Mi7ios, remark : — 

 "The author founded this genus on theTasmanian shell Fossarina 

 petterdi; he placed it in tlie family Stomatidse, but the 'horny 

 multispiral operculum, the dentition resembling Cantharidus,' and 

 the porcellaneous, somewhat iridescent interior, induce us to place 

 it in the vicinity of Gibbula.'"-' The complete closure of the aper- 

 ture by the operculum strengthens this classification. Its right 

 place seems to be between Gibbida and Margarita, with which the 

 internally iridescent species Fossarina legrandi, Petterd,^" seems 

 to connect it, and with which it may even prove synonymous. 



The result of the these investigations, then, is that Minos is a 

 synonym of Fossarina, and that the genus should be placed in 

 the Trochidse, between Gibbula and Margarita. 



8 Tryon— Man. Conch., ix., 1887, p. 275. 



9 Tate and May— Proc. Linn. Soc. N.S.W., (2), xxvi., 1901, p. 403. 



10 Petterd— Journ. Conch., 1879; Tate and May— Loc. cit., p. 404., pi. 

 xxiv., f. 21, 22. 



