The File Shells i 



pebbles have place. Strangely enough, two or three young ones 

 may be found in one nest, but adults are alone, in such close quar- 

 ters that they cannot turn around without the greatest eflfort. 

 But they are able to move up and down, as the nest is funnel- 

 shaped. They retire when prowling crabs and hungry fish ap- 

 proach. 



The Oriental File Shell {L. orienlalis, Ads. andKvQ.) is iound 

 with its interesting nest attached to stones well off our west 

 coast. Mrs. Oldroyd described one she took from the dredge 

 at San Pedro, and put into a jar of sea water. It came out of 

 the nest and swam gracefully about, occasionally putting the 

 foot out as if to help it along. The white shell, obliquely oval, 

 and set with rows of fine, file teeth, had rose pink mantle fringes, 

 short but numerous, which merged into white for one-third of 

 the border. This species is L. dehiscens, Conr. Length, i to 3 

 inches. 



Habitat. — Monterey southward, California. 



The Gaping File Shell (L. hians, Gmel.) has strong, rough 

 ribs, and in all particulars seems able to take care of itself. The 

 body is red, and the mantle orange, trailing a thousand long 

 filaments, that curl and twist constantly, like the tentacles of a 

 sea anemone. In the nest of this species the little porcelain 

 crab lives, with full consent of the owner. It probably acts as 

 scavenger, keeping the house clean in exchange for its lodging. 

 Length, 2 inches. 



Habitat. — British Isles. 



The Fragile File Shell (L. Loscombii, Sby.) small, finely 

 ribbed, and delicate, with bright orange body and tentacles, lives 

 on muddy bottoms from shallow water to one hundred fathoms 

 depth. Cod and other fish are very fond of this little bivalve. 

 To escape the enemy it bores holes in clay bottom to hide in. 

 Nests cunningly covered with bits of shells and other debris are 

 built where the bottom is too hard to burrow into. Length, 

 1 inch. 



Habitat. — British Isles. 



The Excavated File Shell (L. excavata, Chemn.) is the 

 largest species now living. Its oval valves are thin and shallow, 

 the surface faintly cross-striated. The posterior ears are well 

 developed ; the anterior ones are drawn in, forming part of an 

 excavated area that is sharply angled on the thickened margin 



409 



