116 BULLETIN OF THE NATURAL HISTORY SOCIETY. 
species, and is nearly as broad as long. It is about half an inch in 
diameter. 
Economics, Probably similar to Xylophaga dorsalis. 
30. Xylophaga dorsalis (Turton) Forbes and Hanley. 
[Xylophaga, wood-eating ; dorsalis, from plates on its back.] 
[The Teredo dilatata of Mr. Whiteaves’ first report, as he- 
tells us in his second,] 
Distribution, (a) General ; — Northern Atlantic ocean. 
(b) In Acadia; — New Brunswick and Nova Scotia waters. 
Mr. Whiteaves says in his first Report, — “ Principal 
Dawson informs me that great damages have already been 
done to the woodwork of wharves and harbors in Nova Scotia 
and New Brunswick, by this species of Teredo. 
Habits. Though in general structure, habits, etc., it is probably 
quite like Teredo navalis, it differs much in appearance. It is from one- 
inch to one and a half inches long and has the organs more concentrated 
than in Teredo, forming a spherical mass from which a slender tube- 
projects backward bearing the siphons. We find it showing characters 
intermediate between the Teredos and the genus Pholas ; the latter are- 
shelled bivalves which bore into stone. This species would hardly be 
distinguished by the beginner from the last. 
Economics, On account of its smaller size, and conse- 
quently short burrows, it is not so destructive as the larger 
Teredos, but it nevertheless does much damage both to floating 
and fixed timber works in Europe. 
Mr. Whiteaves says in his first Report, — “Mr. Nelson 
Davis, of Montreal, tells me that the brigantine ‘ Magdala/ 
which was built at St. John, N. B., was completely riddled 
by this ship-worm some time ago, on her first voyage from 
St. John to Liverpool The whole of the ship’s 
bottom had to be renewed and covered with copper sheeting 
before she was again seaworthy.” 
