218 



Ijiagjiosis. — From Nacdla crehristriata, Verco ; it is less 

 solid, more rounded, has its apex less excentrie, and fewer 

 and less valid ribs. From Scutellina calva, it is narrowed 

 anteriorly, has no crowded axial lirae, is white-ribbed. From 

 Cocct/Jina fasmanica, Tate and May, its apex is more central 

 and leans backwards. 



Ohs. — In some examples the opaqne radii are much nar- 

 rower, or a wide and a narrow one may alternate. The opaque 

 lines are not continuous, but cv^mposed of arrow-heads, with 

 their points towards the margin, or of zig-zags, or dots. 



Its generic location is somewhat dubious. 



Family TROCHID^. 



Genus Basilissa, Watson. 



Basilissa radialis, Tate ; var. bilix, Hedley, «p. 



PI. X., figs. 1, 2, 3. 



Seguenzia radialis, Tate, Trans. Roy. Soc., S.A., xiii. ; 1890. 

 p. 192, pi. ix., f. 6. • 



Astele hilix, Hedley, Records Austr. Mus., vi., pt. 2, 1905, 

 p. 48, f. 13. 



Shell depressedly conical, of seven and a quarter whorls, 

 including a homostrophe smooth protoconch of one and a 

 quarter whorls. 



Spire somewhat gradate. In the first whorl one marked 

 spiral rib ; in the rest two becoming gradually more valid and 

 distant. In the third whorl a secondary threadlet between 

 these : in the fourth a threadlet between the first 

 spiral and the upper suture ; in the fifth two terti- 

 avics, one between each spiral and the secondary threadlet. 

 In the sixth, or body- whorl, another spiral rib appears below 

 and nearly equal to the lower of the two spirals : it forms the 

 peripliery and the suture, and, separated from its fellow by a 

 furrow, gives an apparent canaliculate suture. The base is 

 flatly rounded with eight equi-distant, nearly equal, concen- 

 tric rounded spiral lirse, as wide as their interspaces. The 

 surface is cancellated by crowded narrow erect lamellce, cross- 

 ing the spirals and sinuous, but not following exactly 

 the outline of the labru:m, and ending at the outer 

 basal lira. Crowded radial strice cancellate and 



granulate the base, and extend to the lira nearest the umbil- 

 icus. Aperture obliquely quadrate, with a larsfe posterior 

 sinus in the outer lip, rather deeper than wide : a second 

 at the baso-labral junction, beginning at the third spiral rib, 

 about as deep as the infra-sutural one, and rather wider : and 

 a third shallow and wide at the baso-columellar angle. Colu- 

 mella ol^lique, concave, expanded towards the umbilicUvS. trun- 



