0 ney 

100 ‘ 
and the roundly elliptical forms. The opinion expressed in 
Trans. Roy. Soc. South Aust., 1906, vol. xxx., p. 207, as to the 
identity of these two species is confirmed. 
KA 0 Genus BREECIONISCUS, Del ee a 
H.-limbatus, Philippi. A220, i 
Patella limbata, Philippi, Abbild. und Besch. Conch., vol. iii., 
P- 71, pl. iii., f. 2, 1849; Reeve, Conch. Icon., vol. viii., pl. xiii., 
. 29, a, b, 1854; Angas, Proc. Zool. Soc. Lond., 1865, p. 185; 
Ten. Woods, Proc. Roy. Soc. Tasmania, 1877 for 1876, p. 48; also 
1879 for 1878, p. 45; Pritchard & Gatliff, Proc. Roy. Soc. Vict., 
vol. xv. (new series), part 2, p. 192, 1903. 
Patella (Helcioniscus) imbata, Phil., Pilsbry, in Tryon’s Man. 
Peek Sol vol. xili., p. 148, pl. lxxi., f. 53 to 56, and pl. xvii., 
Hab.—That of the type is given by Philippi as “New 
Holland” (Largilliert); Reeve records it from “Signet Bay, 
North Australia: Dring”; Angas, “Port Lincoln, South Aus- 
tralia’; Ten. Woods, “Southport, Tasmania”; Pritchard and 
Gatliff, “Cape Otway, Victoria.” It has been taken at the 
Neptunes and Thistle Island, and in Spencer Gulf by Dr. 
Torr; on Yorke Peninsula by Mathews; at Encounter Bay by 
myself. I did not find it at Kingston, Robe, Beachport, or 
MacDonnell Bay. 
Dim.—The largest dimensions given by Ten. Woods are. 
71 mm. by 64 by 32; but one from Yorke Peninsula measures 
77 by 64 by 33. 
Philippi, Reeve, Angas, Pilsbry, and Pritchard & Gat- 
liff regard it as a good species ; but Ten. Woods in 1878 wrote: 
“T regard this shell as a variety, or not even a variety, of the 
preceding (2. tramosericus, Martyn). The somewhat broader 
ribs may distinguish it.” Tate & May in their census of 
the Marine Moll. of Tasmania, Proc. Linn. Soc. of New South 
Wales, vol. xxvi., 1901, p. 141, accept this view. Among the 
shells collected by Dr. Torr in Spencer Gulf is a facsimile of 
Philippi’s type figure, in shape, size, colour, and erosion. 
Others, up to 55 mm. in length, have the apex perfect. In- 
stead of being yellowish they may be of a deep salmon tint, 
and instead of 32 may have only 22 ribs, much broader than 
in the type, and thus differ still more than this from P. tra- 
moserica, Mart. On the other hand, a unicoloured salmon-tint- 
ed shell from Beard Peninsula, West Coast of South Austra- 
lia, in its ribbing comes between both species ; and a small shell 
from Encounter Bay in its shape and flat rounded ribs ap- 
proaches H. limbatus, and yet in its 44 ribs and red, yellow, 
and black radial markings is allied to H. tramosericus. I 
lean to the view of identity with extreme variation ; but my 
series is not very large, and does not furnish such gradations 
as to warrant an absolute conclusion. 
