SHIP WORM OA^ ATLANTIC COAST 97 



SESSIONAL PAPER No. 38a 



region where this form has been noticed is at Oexfjord in West Finmark, where my 

 father found it boring in piles." 



This Finmark colony of Teredo norvegica is far to the north of the northern 

 margin of the continuous distribution zone of the species on the Norwegian coast. 



B. Saumundsoni writes as follows regarding the occurrence of Teredo in Ice- 

 landic waters : " The Icelandic name of Teredo, ' tremadkur,' was first mentioned as 

 Icelandic by E. Olafssen in his journey through Iceland Soroe in 1772: 'Teredo 

 navalis intra lignum is the bad worm, which spoils the driftwood' (West Iceland). 

 Later it is mentioned by Mohr, 1786 (Icelandic Natural History) and by Morch 

 (Fauna Mollusc. Island), 1868, both on the authority of Olafssen, so that neither of 

 these two men have noticed it in Iceland themselves. 



The species was found living in a pier at Keykjavik by me five years ago, and 

 definitely determined by Ad. Jensen as T. norweviga Spengl. 



The species is found in driftwood all around the island. It was found by me 

 only in standing lumber (piers) at Eeykyavik (West coast)." 



A Teredo listed as T. navalis? and T. denticulata is included in Mollier's'- and 

 Morch's^ lists of the mollusca of Greenland. Posselt-* refers Moller's T. navalis 

 to T. denticulata which he records from a single locality in S. Greenland, — avigtut. 



The distribution of Teredo navalis along the Atlantic coast of Canada and New 

 England aifords an excellent example of discontinuous distribution. The essential 

 features of this distribution are indicated in the sketch map (fig. 2), showing the 

 distribution of Teredo in these waters. The map includes south of the Bay of Fundy 

 liie recorded occurrences of two or three species besides T. navalis but it clearly 

 shows that the coast line distribution of this species is broken by 400 miles or more of 

 coast line along which it is either absent or very rare. This mollusc is present in 

 great abundance around the southern shores of the gulf of St. Lawrence and the coast 

 of Cape Breton island. But southwest of the Str. of Canso it becomes scarce. In the 

 Bay of Fundy, T. navalis is either very rare or entirely absent. South of this bay, 

 however, it again becomes common on the Maine coast and from Frenchman's bay 

 s uthwest appears to be generally present along the New England coast. 



Mr. H. E. Miller has furnished the following notes on the distribution of 

 T. navalis on the coast of Prince Edward Island: "Teredo is present in all waters 

 surrounding the Prince Edward Island and up the inland tidal waters as far as the 

 salinity of the water is sufficient. 



" Eegarding the coast of New Brunswick to the westward of this province, I 

 cannot speak from personal observation never having visited that coast but from what 

 1 can learn the borer is to be found along the whole coast of Miscou and Shippigan 

 and for at least a short distance along the Chaleur Bay coasts. I understand they 

 do not work as far up to the rivers, as in this province. This is readily understood 

 from the fact that the rivers are practically fresh very nearly to the outlet, draining 

 immense areas and salinated by a very small range of tide. 



" At Eustico Harbour on the North side of the island, there is great activity. The 

 Iccality is entirely sandy. At Tignish, on the other hand, another sandy locality, the 

 destruction is much less, but there is a very strong current, much sand in suspension, 

 and considerable fresh water. The same comparison is true between localities of a 

 muddy nature. Considering two localities, one sandy and one muddy, each with a 

 considerable constant suspension of the material forming the bottoms, the destruc- 

 tion appears to be greater in the sandy locality."^ The photograph here shown in fig. 

 1 indicates the great activity and abundance of T. navalis at Charlottetown on the 

 south coast of the island. 



1 Letter to the writer. 



2 Index MoUuscorum Groenlandica, 1842, p. 21. 

 3Middelelser au Gronland, Vol. XXIX, 1905, pp. 2S9-362. 

 4Meddel. on Gronland, Band 23, 1898, p. 101. 



