370 



On and 'above the peripheral keel of the outer volution the whole sur- 

 face is finely cancellated by minutely tuberculated ridges, which are so 

 arranged as to form regular, equidistant and parallel, obliquely transverse 

 rows, as well as distinct spiral ones. Near the aperture, there are seventeen 

 of these spiral rows of tubercles. Below the peripheral keel there is one 

 spiral ridge and numerous, rather coarse, obliquely transverse growth 

 lines but there are, apparently, no tubercles upon the base. In the 

 largest specimen collected (figure 7) the outer volution, next to the suture 

 above, is partially encircled with a narrow, erect, spiral fold or plication, 

 crossed by oblique non-tuberculated ridges and strire, as well as by the 

 peripheral alation. 



Roof of coal, Nanaimo mines, W. Harvey, 1901 : three specimens, 

 which are only provisionally and rather doubtfully referred to H. Adams' 

 genus Plianeta. In many respects they agree very well with the generic 

 and specific description, and with the figures, of P. Everetti, H. Adams, 

 in the twelfth volume of Tryon's Manual of Conchology, but in Phaneta 

 the suture is said to be distinct, the aperture is represented as channeled 

 at the peripheral keel, and the upper surface is not minutely tuberculated. 

 Moreover P. EverefM, the type and hitherto only known species of the 

 genus, is known to be a fresh water shell, whereas the Nanaimo specimens 

 are presumably marine, as they are found associated with such purely 

 marine genera as Crassatella, Pectunculus, Nucula proper, Acila, Leda, 

 Ginulia, Trochactceon, &,c. The sculpture of their upper surface is very 

 like that of some species of Calliostoma and Turciada, but their lower 

 surface, including the mouth, is more like that of such a typical Stomatella 

 as S. imbricata. They may indicate a new generic type of Trochidaj or 

 Stomatellidfe, for which the name Euphaneta might be appropriate. 



Helcion giganteus 1 var. Vancouverensis. 



Plate 51, fig. 1. 



Cfr. Helcion giganteus, Schmidt. 1873. Ueb. die Petref. der Kreide-form. von SaehaliSi, 

 p. 19, pi. 2, figs. 17, 18 ; pi. 3, figs. 1--10 ; and pi. 8, figs. 2-5. 



Shell very large, patelliform, depressed conical, apex eccentric, placed 

 very near to the anterior margin, but not quite marginal, aperture a little 

 longer than wide, rounded subovate, or nearly circular but somewhat 

 pointed behind. 



Surface marked with concentric lines of growth, and low rounded 

 radiating ribs or plications, that are faint and almost obsolete centrally, 

 but fairly well defined around the outer margin. 



The specimen described is about four inches in length, and very little 

 less in breadth. 



