96 Gabriel, Exotic Mollusca found at Coode Island. [sepVember' 



NOTES ON EXOTIC MOLLUSCA FOUND AT COODE 



ISLAND, WITH LISTS OF SPECIES. 



By C. J. Gabriel. 



{Read before the Field Naturalists' Club of Victoria, 14th August, 191 1 .) 

 In May last a most interesting paper was read before this Club 

 by Mr. J. R. Tovey, of the National Herbarium. ^Melbourne, 

 entitled 'Notes on Coode Island and its Flora" {Vict. Nat., 

 xxviii., p. 56), in which he gave a general description of the 

 locality, dealing with the early history of the site and the 

 formation of the island in September, 1886. This description 

 is so accurate that there is no need for me to add any further 

 particulars. 



While commenting on the occurrence of so many foreign plants, 

 Mr. Tovey stated that ships' ballast had been deposited there, 

 and might be responsible for the introduction of these aliens, 

 adding that a visit to Coode Island would probably repay the 

 conchologist. His remark recalled to my mind the fact that, 

 in 1900, a vessel from Durban, South Africa, deposited some 

 ballast shells on our shores — first at Geelong, again coming up 

 the bay, and finally on the roadway adjacent to the Alfred 

 Graving Dock, Wifliamstown. This action has caused, and 

 may continue to cause, trouble in the matter of these shells 

 being regarded as belonging to our local fauna. Hence, I con- 

 sidered the statement significant, and of sufficient importance 

 to warrant a careful examination of the locahty. 



In company with a fellow-member the spot was duly visited, 

 but the only "ballast" noticed contained representatives of our 

 Victorian shells, which I have recorded in the July Naturalist 

 (vol. xxviii., p. 50). These shells were i^robably contained in 

 material carted there from the neighbourhood of St. Kilda or 

 South Melbourne when filling in the island. On communicating 

 this fact to Mr. Tovey, he suggested that possibly we had 

 hunted the wrong ground — a contention which eventually proved 

 correct, as, when a second visit was made along with him, a 

 collection of some sixty species of foreign mollusca was obtained. 



The spot in question is situated about two hundred yards 

 from the south-west corner of the island, and nearly opposite 

 Cuming, Smith's chemical works ; but Mr. Tovey found the 

 surroundings entirely changed since his last visit, a few months 

 before, inasmuch as the ballast heaps observed on that occasion 

 had been spread, and were now overgrown with the introduced 

 South African Spinach, Tetragona procumbens. Still another 

 trip was made, when the number of foreign species was aug- 

 mented to 121. Here and there patches of ballast remained un- 

 covered—these were thoroughly searched, and yielded an 

 interesting collection of two distinct faunas. The quaint little 

 Nassa kraitssiana, Dunker, found in numbers, and Patella 



