8 



III. IIATURAL HISTn^v op THE "SIIIP-WORI'.^S" . 



Any wooden structures that one may examine at Beau- 

 fort, which have been in the \rater for some time and un- 

 protected, are alv/ays foimd infested with "Ship-wonns ". 

 These are of three species, which Professor V/. H. Dall has 

 kindly identified for me as Xylotrya fimbriata, Jeffreys, 

 Teredo navalis, Linne and T. norvegica, Spengler. X. fim- 

 briata and T. norverica are very abundant, v/hile T. nava- 

 lis is fouj^d but rarely. X. f i^^^r^ •'tPi, is the most abund- 

 ant of all, and is found everywhere. It may attain a 

 length of tv/o feet, though where it grows in large niunbers 

 it is 30 crowded that specimens are oftener less than a 

 foot in length. T. norvegica I have found mostly in the 

 heavier piles of wharves, v/here specimens may attain the 

 great size of four feet in length and an inch in diameter. 

 T. navalis I have found very sparingly, not over a dozen 

 specimens among the thousands of individuals I have exam- 

 ined. These in all cases were small specimens, from which 

 it seems that the habitat at Beaufort is not favorable for 

 them, and is more favorable for the other tv/o species 

 v/hich fully occupy all of the available places for "oliip- 



