215 



curved, and in having much finer and more crowded stria?. It 

 differs from .1. siihtniduKua , Angas, in being less elevated, 

 less orbicular, with a sharper and more antecurved apex, and 

 in its colour. 



Acmaea septiformis, Quoy and Gaimard. 



ratelluida septifurinis, Quoy and Gaimard, Voy. Astrolabe, 

 Zool., 1834, vol. iii., p. 362, pi. Ixxi., iigs. 43, 44; Lamarck, Anim. 

 s. Vert. (2nd edition, Deshayes, etc.), 183(5, vol. vii., p. ooO ; 

 Tectum scp.tlforiiiis, Q. and G., Angas, Proc. Zool. Soc, Lond., 

 18()7, p. 220, No. 219; Acmoea septiformi,^, Q. and G., Ten. -Woods, 

 Proc. Hoy. Soc, Tasni., 1877, p. oO ; Pilsbry., Tryon, Man. Conch., 

 vol. xiii., 1891, p. 55, pi. xxxvii., figs. 93, 94: Adcock, Handlist 

 Aquatic xMoll. S. Aust., 1893, p. 9, No. 397; Tat-e and May, Proc. 

 Linn. Soc., N.S.W., 1901, vol. xxvi., p. 412; Pritchard and Gat- 

 liff, Proc. Roy. Soc, Vict., 1903, vol. xv. (n. s.), pt. 2, p. 195. 



.1. scaJ}rilirata, Angas, Proc. Zool. Soc, 1865, p. 154, and p. 

 186, No. 201: Pilsbry., Tryon, Man. Conch., 1891, vol. xiii. p. 

 56 ; Pritchiard and Gatliff , lot. cii. 



A. petterdi. Ten. -Woods, Proc. Roy. Soc, Tasni., 1877, p. 

 155; Pilsbry., op. cit., p. 54; Tate and May, loc. cit.; Pritchard 

 and Gatliff, loc. cit. 



Obs. — Tate and May say A. petterdi is the senile form. 

 The shell varies in altitude from 18 mm. long, and 4*5 

 mm. high, to 14 mm. long and 6 mm. high. Some have a 

 cap occupying up to one-third or one-fourth of their size, with 

 comparatively steep sides, with an abrupt assumption of the 

 ordinary depressed shape, looking like one acmcea mounted on 

 another. The base is in some uneven, resting on the front 

 and back edges possibly because their roost was not flat. The 

 radial lirse may be marked from aj^ex to base, and numer- 

 ous, or very few, or absent, even when not rolled or eroded. 

 The surface may be uniformly horn -coloured, or white, with 

 radial black-brown widening bands, or with reticulated or 

 roundish tessellated markings. The inner margin may be 

 articulated brown and white, or have a uniform brown mar- 

 gin or be wholly white. The interior may be whitish, 

 opaque glistening white, bluish- white, or with the outer col- 

 our showing through. The spatula may be dark chestnut- 

 brown and very distinct, or almost invisible. 



The surface is generally in very good condition, but some 

 are markedly pitted with round shallow holes, especiallv about 

 the summit, evidently due to boring by molluscs, and not to 

 erosion. 



Locality. —From Port MacDonnell to Fowler's Bay ; 

 rather common. 



Acmsea cantharus, Reeve. 

 Patella cantharvs. Reeve, Conch. Icon., vol. viii., 1855, pi. 

 xl., f. 131: Pritdiard and Gatliff , Proc. Roy. Soc, Vict.. 1903, 



