211 



tude varies very greatly from 3'5 mm. in a sliell 17 mm. 

 long to 8*5 mm. in one 18 mm. long. When on the rocks they 

 may be so rough and acutely costate as to be mistaken for A . 

 cdticoi^tafa, Angas. Usually with a flat bavse, it may rest on 

 its ends, with the sides of the border much raised. As vari- 

 ations from the description by Ten. -Woods, the spatula may 

 be white, with some brown clouding in its centre, the interior 

 of the shell being a light brown, or the spatula may be black 

 and the rest ©f the interior white except for black articula- 

 tions of the border. The most constant feature in the orna- 

 ment is the dark dotting: of the spatula, but in the pall id 

 examples this is very slight. 



Adcock makes P. gealei, Angas, a synonym, and Pritch- 

 ard and Gatliff give it priority, and .4. marmorafa a5 a 

 synonym : but Angas's shell is a distinct species. P. latistri- 

 rjnfa, Angas, from Aldinga, is a half -grown example, witli 

 broad radial stripes. 



Acmaea calamus, Crosse and Fischer. 

 rateUd caldinti.'i, Crs. and F., Journ. de Conch., 1864, p. 

 348; 1865, p. 42, pi. iii., figs. 7, 8; Tate and May, Proc. Linn. 

 S(x;., N.S.VV., 1901, vol. xxvi., pt. 3, p. 412; Acmcea calamus, Crs. 

 and F., Angas, Proc. Zool. Soc., Lond., 1865, p. 186, No. 200; 

 Pilsbry., Trvon, Man. Conch., Ib91. vol. xiii., p. 54, pi. xxxvii., 

 figs. 3, 4; AdoGck, Handlist Aquatic Moll., S. Aust., 1893, p. 9, 

 No. 395; Pritchard and Gatliff, Proc. Roy. Soc, Vict., 1903, vol. 

 XV. (n. s.), pt. 2, p. 197. 



Locality of type, St. Vincent Gulf, South Australia. I 

 have taken it at Port MacDonnell, and dredged it from Back- 

 stairs Passage to Spencer Gulf, alive, at all depths from 5 to 

 17 fathoms. Most abundant in the shallower water. 



Tate in Trans. Roy. Soc, S. Aust., May, 1897, thought 

 it would prove to be a synonym of A cnuea conoidta, Quoy 

 and Gaimard. and this suspicion seems to have been con- 

 firmed, as he lists it thus in his Tasmanian Census in 1901. 

 He speaks of A. conoidea, in 1897, as though he had seen 

 Quoy's type, and as having a circular aperture and five 

 radial threads. But Quoy seems to have only had one shell 

 collected at King George's Sound. This Deshayes had not 

 seen (Anim. S. Vert., 2nd edit., vol. vii., p. 551), and Quoy 

 does not describe it as having any radial threads, but as being 

 "obtuse and rounded at the apex" : this A . calamva never is, 

 either alive or dead or rolled. 



The dimensions given by Crosse are 12'5 mm. by 10 by 6, 

 but they reach 16'5 by 14 by 7'5. The shell may be whollv 

 white within and without, or the apical part may be whit-e 

 and the rest ornamented, either with tinv brown spots, more 

 or less abundantly and iiregularly scattered over the surface. 



