Notes on South African MoUusca. 145 



material sent home by the earlier collectors, left some valuable 

 manuscript notes on the distribution of the Trigonephri, which, 

 by Mr. Ponsonby's courtesy, I am enabled to publish. The record 

 of T. globulus on Green Point Common is renrarkable, as the species 

 is now unknown there, having been completely ousted by the 

 introduced H. pisana, Miill. 



It will be noticed that Layard wrote in the days when only three 

 species had been described, and he attributed every form to one or 

 other of them, but this detracts but little from the interest of his 

 notes, to which I shall have course to refer later. 



"Helix globulus, MilU. — Various forms of this very variable shell 

 are found on all sandy plains along the seaboard from Cape Agulhas 

 to Walfisch Bay and Namaqualand. During the dry summer season 

 they lie concealed, buried to a considerable depth in the sand, but 

 on the fall of heavy rain they emerge from their retreats in thousands. 

 I shall never forget my first sight of the living shells. I had found 

 the sandy plain near Cape Town, known as Green Point, covered 

 with the dead, bleached shells, but not a live one could I procure. 

 Some friends even hinted at their being fossil and extinct, but I 

 asserted they were too fresh-looking for that, and waited for the 

 rains. They came, and I sallied out in the downpour, calling on an 

 enthusiastic friend, C. A. F., to accompany me. On getting on to 

 the Common, past the Battery, we found the surface of the ground 

 literally heaving with the swarms coming up ! They were every- 

 where ! We gathered our handkerchiefs full, and as they emit a 

 most copious, clear slime, we were soon covered with the sand 

 which adhered to it and wet from head to foot with the pitiless 

 downpour, and presented a draggle-tailed spectacle ; but we agreed 

 that the sight of tens of thousands, emerging from their long sleep, 

 repaid us for all our dirt and discomfort. 



"The specimens found near Cape Town, Kalk Bay and the 

 Cape Flats may be taken as of fair medium size. They are about 

 31 X 29 mm. On Eobben Island, a sandpatch in the mouth of Table 

 Bay, there is a fine large variety, similar in colour, 38J x 10 mm. 

 In Nord Hoek, not far from Kalk Bay, I took a small variety, fully 

 formed shells varying from 25| x 19| to 15x15 mm., shells purely 

 white. In the George District there is a small variety, 19 x 19 mm., 

 with a pale purple, or puce-coloured mouth. Another variety, prob- 

 ably from Algoa Bay, rather larger, 27| x 25^ mm., is much darker 

 in the mouth, and the apex is also dark bluish purple. 



"These seem to lead into the large solid shell, with the broadly 

 recurved, heavy, purple lip, from Namaqualand, named rosacea by 



