26 AUSTRALIAN L.VXD SHELLS. 



capillacea all those shells of the Port Jackson type, with the spire 

 flat, or nearly so, and for the group, much depressed, and finely and 

 closely ribbed, without any decussating spiral lines. 

 I possess a large specimen from the shores of Port Jackson, l - 00 by 

 - 85 of an inch, veiy rudely sculptured, and from the prominence of 

 the lines of growth evidently an old shell, in which there are no 

 spiral lines, and where the spire is quite flat. 



66. Helix Strangei. Pfr. Plate XTIII. Fig. 17. M.C. 

 Pfr., Pro. Zool. Soc, 1848, p. 108. 



Peeve, Cone. Icon. sp. 416. 



Shell umbilicated, depressed, rather thin, shining, pellucid, closely 

 striately-ribbed above, decussated with very numerous impressed 

 spiral lines, yellowish, reddish, or chestnut-horny ; spire slightly 

 elevated, obtuse ; whorls 5, slightly convex, last large, tumid, de- 

 pressed above, convex externally and below, not descending in front; 

 base nearly smooth, with obsolete indications of strire and concentric 

 lines, very glossy ; umbilicus rather large, about 1 -5th of the 

 diameter, pervious ; aperture moderately oblique, lunately-oval 

 within, somewhat pearly ; peristome simple, thin, straight, margins 

 approximating, right rather straight, outer regularly arched, colu- 

 mellar margin thinly expanded, and reflected above. 



Diameter, greatest 1*05 ; least 090 ; height - 40 of an inch. 



Habitat. Brisbane Water. Lane Cove. Penrith. Also Clarence, Rich- 

 mond, and other rivers, as far north as Port Denison. Cox. 



This species is subject to considerable variation. The spiral decus- 

 sating lines are sometimes absent, thus indicating a passage to H. 

 capillacea ; but these specimens are not so depressed, nor is the spire 

 so flat ; usually the shell looks as if varnished, and the rib-like 

 stripe, except towards the apex, are never so prominent as in H. 

 capillacea ; indeed, the last are occasionally almost obsolete, as in 

 a specimen from Ash Island, Hunter Eiver. Examples from the 

 brushes often exhibit, especially on the under surface, a fine deep 

 chestnut hue, and in such situations this shell attains to its greatest 

 dimensions. The measurements, however, are not those of one of 

 the largest size. 



67. Helix bullacea. Pfr. Plate IY. Pig. 11 ; and Plate II. 

 Fig. 10. M.C. 

 Pfr., Pro. Zool. Soc, 1854, p. 53. 



Peeve, Con. Icon. sp. 1288. 



Helix assimilans. Cox, Pro. Zool. Soc, 1864, p. 593. 

 Shell umbilicated, convexlv-depressed, thin, glossy, pellucid, above 

 very closely set with distinct thread-like stri?e, reddish-horny ; spire 

 small, slightly convex ; whorls 4, quickly increasing, rather con- 

 vex, last rounded and smooth at the periphery, slightly depressed 

 above at the mouth, rather inflated outwardly, not descending in 

 front ; base convex, very faintly radiately striated, yellowish-horny, 

 very glossy ; umbilicus modeiate, 1 -5th of the diameter; aperture 

 diagonal, almost roundly-lunate, slightly iridescent within ; peris- 

 tome simple, thin, straight, margins convergent, sometimes joined 



