(2) 



the shelly processes in Xylotrya, or si- 

 phonal palettes, as they are called, are 

 long and penniform, or shaped like a 

 quill or feather; to this group belong 

 the three species of ship-worms found 

 in California — Xylotrya pennalifera, 

 Xylotrya Jlmbriata, Xylotrya setacea. The 

 first and second of the species enumer- 

 ated are said to be found in England as 

 well as on our coast, while the third spe- 

 cies is less widely distributed, and is re- 

 ported from San Francisco Bay to San 

 Pedro. As before stated, all of the spe- 

 cies of ship-worm found thus far in Cali- 

 fornia, belong to the genus Xylotrya, and 



may be distinguished by the two plume- 

 like processes or palettes at the end of 

 the siphons. The destruction caused by 

 the Xylotrya (or wood-fish, as the gen- 

 eric AYord means), is too well known to 

 rerpiire comment. I have known a per- 

 fectly sound pile of Oregon pine, of a 

 diameter exceeding twelve inches, to be 

 rendered utterly useless in eighteen 

 months by their ravages, while the 

 wood elsewhere than within the section 

 of the pile eaten and bored by them, 

 was as sound and bright as on the day 

 that the pile was driven; this instance 



is, however, extraordinar3^ The Teredo 

 navalis, to which our ship-worm is fre- 

 quently referred by local writers, is a 

 foreign species, and the stylets are 

 paddle-sha^Ded, instead of penniform as 

 in the California sjiecies. 



The third group of the Teredines is 

 the Uperotis. In these, the shelly valves 

 and palettes are the same, but the tube 

 is twisted and club-shaped from the an- 

 imal burrowing in the husks of cocoa- 

 nuts which are found floating in tropical 

 seas. 



The ship-worms are ovo -viviparous, 

 the eggs being hatched in the body 

 of the parent, and ejected therefrom 

 through the upper siphonal tube. The 

 young ship-worm, like the young oys- 

 ters and others of the bivalve mollusks 

 {Conchifera)j syfim freely for a time until 

 they pre-empt or fix upon a j)ile or other 

 submarine woodwork, when they com- 

 mence burrowing. While doubtless a 

 great deal of damage is done by them, 

 nevertheless, as is observed by the 

 brothers Adams, "they are useful 

 agents in breaking down and destroy- 

 ing fragments of wrecks and floating 

 timber, which otherwise might be dan- 

 gerous impediments to navigation." 



The ship-worms are frequently two to 

 three feet in length, the body quite soft, 

 but protected by the shelly coating 

 which is deposited by them upon the 

 sides of their burrow, forming a tube, 

 to which, however, in the recent (not 

 fossil) species the body is not attached; 

 the boring is done with the foot, but 

 whether with the shelly valves, which 

 are shaped much like the nibs of a pod- 

 augur, or by some other process, is not 

 by any means a settled question. 



In our species the shelly tube is so 

 thin that it is impossible to sjilit the 

 wood without shattering it, but in one 

 species, the Teredo gigantea, or giant 

 ship-worm of Linnoeus, the tube is often 

 ' a yard long, and two inches in diame- 



