57 . 
S.A. NAT., VOL. XVI. 
Juiy 24, 1935. By Bernard C. Cotton and F. K. Godfrev. 
Francis Island. Dredged alive — Yankalilla Bay; off Troubridge 
Island; Investigator Straits; Backstairs Passage; 13 to 22 fath- 
oms. Also Western Australia — Beach, Albany, Yallingup. Dredg- 
ed — King George Sound, 35 fathoms, one example. (Type loc- 
ality — Port Jackson). Varies much in colouring. The foot of 
the animal is nearly as long as the diameter of the base of the 
shell, about one third as wide, and rather pointed posteriorly. 
It is opalescent white in colour with an opaque white dotted mar- 
gin. Two obscure purple blotches are seen through it on either 
side. The tentacles are as long as the foot is wide, white, with 
black eyes on the outer edge of their bases. Two long cilia are 
visible. 
Gibbula preissiana Philippi 1S48 ( Trochus ) (= Gibbula 
porcellana A. Adams 1851: = G. weldii Tenison-Woods 1877). 
Orbicular-depressed, rather thick, deeply umbilicated; whitish 
with conspicuous flexuous rosy-brownish lines and remote spots 
at the suture and periphery; first whorls smooth, the following 
spirally, delicately sulcate, with an elevated ridge in the middle; 
last whorl bicingulate, the cinguli elevated, distant; whorls five 
to five-and-a-half, separated by profound sutures; base convex, 
concentrically lirate, the lirae larger around the umbilicus; um- 
bilical area sulcate and fumculate within; aperture subrotund; 
columella arcuate, not dentate. Height 6 diam 7 mm. Not 
Gibbula preissiana Philippi x 3J. Radula on right. 
common. Beach, Grange, Port Willunga, Kangaroo Island, and 
westward to Pondalowie Bay, Venus Bay, St. Francis Island. 
Als° > Western Australia— Beach, Albany to Bunbury. (Type 
locality Gulf St. Vincent). Radula formula 0:1 1. (5.1.5) 1. sc 
Very fine and threadlike. Of the central teeth the middle ’one 
is broad and has a flange on each side of its base, the rest have, 
each one cusp with a fine serrated edge and a single flange on 
its outer side; the outermost differs slightly from its fellows, 
le single lateral is small and simple. The marginals have lon^ 
narrow bases and two cusps, of which the larger has a serrated 
edge. 
