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THE GUIDE TO NATURE 



.in unusual one. It consists as you have 

 stated of a mass of serpular tubes, with 

 a bryozoon growing on the outside of 

 them. It is a common thing for the 

 bryozoons to form a crusting material 

 like this over a variety of solid objects, 

 and this bryozoon, having a lime shell, 

 always appears porous in this way after 

 the animals have died. What you have 

 therefore is simply a mass of serpular 

 tubes over which there have been 

 growing a good many generations of a 

 common encrusting bryozoon, and then 

 after the death of the animal the soft 

 part disappearing leaves the porous 

 mass of shells such as you have here. 

 Careful examination of specimens 

 shows a great many layers of these 

 bryozoon shells, indicating that the ani- 

 mals have been growing for a long 

 time, forming layer after layer of crust, 

 one outside of the other. — Professor H. 

 W. Conn, Laboratory, Middletown, 

 Connecticut. 



That one who does not stand so near 

 to any man as to see the divinity in him 

 is truly alone. — Thoreau. 



The Ship-worm is Clam-like. 

 Atlantic City, New Jersey. 

 To the Editor : — ■ 



I send you some particularly line 

 samples of teredo work found on the 

 shores here. Want to photograph 

 them, and give us a talk on the tere- 

 do's work on our old wooden ships, 

 etc.? 



Cordially, 



G. M. Gould. 



THREE VIEWS OF TEREDO BORINGS. 



The best "talk"' on the teredo is in 

 Mayers "Sea-shore Life" as follows: 



"The ship-worm, or teredo, is not 

 a worm but is closely related to the 

 clams. Its peculiar elongate form and 

 worm-like appearance are due to its 

 habit of burrowing into any sort of 

 wood, excepting palmetto logs or teak. 

 The ship-worm begins to burrow into 

 the wood by movements of its foot and 

 shell, when only as large as a pin's 

 head, so that the opening to the burrow 

 is small. For a short distance from 

 the entrance inward the burrow is apt 

 to be perpendicular to the surface, but 

 it soon turns and runs more or less 

 in the direction of the grain of the 

 wood, although usually quite twisted. 

 The burrow is lined with shelly ma- 

 terial secreted by the teredo, and it is 

 interesting to observe that no matter 

 how numerous the teredos infesting a 

 piece of wood, their tubes remain sep- 

 arate one from another and never in- 

 tersect. The shelly material lining the 

 tube is not the true shell of the teredo. 

 The true shell is found at the head-end 

 of the body which is farthest in from 

 the opening to the burrow. Its two 

 valves are small, white and delicately 

 sculptured. The long, worm-shaped 

 body is yellowish-white and tapers 

 gradually to the posterior end which 

 is near the opening of the burrow. The 

 two long, extensible siphons are found 

 here ; and on both sides near their base 

 are a pair of shelly flappers which 

 serve to close the opening of the bur- 

 row when the siphons are withdrawn. 

 A thick muscular collar at the base 

 of the flapper also assists in closing the 

 opening. 



"The teredo does not eat the wood 

 into which it bores and is, therefore, 

 but little affected bv poisoning the tim- 

 ber. The most efficient protection is 

 copper sheating. Species of teredo are 



