214 WEST AMERICAN SHELLS 
ing under the microscope that it is made up of 
many small rings. 
Caecum crebricinctum, Cpr., the Close-ringed 
Tube-shell, resembles the last species, but is nearly 
twice as large and is marked with exceedingly fine 
rings, sometimes quite indistinct. Both of these 
species are found in the south. 
Vermetus lituélla, Moreh, the Crooked Worm- 
shell, (Spiroglyphus lituella). This singular 
mollusk has an irregular, tubular shell, which be- 
comes attached to the side of a stone, and twists 
itself into an ill-shaped, flattened cone. Several 
specimens are frequently found near one another. 
The shell is often angular and roughened; the 
aperture is circular, and is one-eighth of an inch 
or less in diameter. The color, as in several of the 
following specimens, is a dingy white. 
Vermétus squamigerus, Cpr., the Scaly Worm- 
shell, (Serpulorbis squamigerus). Very irregu- 
lar; frequently many specimens grow together 
upon a rock, and look like a heap of contorted 
snakes. The shell is marked throughout its length 
by transverse, scaly ridges. The aperture is cir- 
eular, one-fourth of an inch across. The tube, if 
straightened, would measure some four inches or 
more in length; it has a circular operculum. I once 
found a few living specimens at Monterey, but it 
is rare so far north. Many of these more uncom- 
mon species may be found by wading into the: 
water at low tide and turning up stones or bring- 
ing them out to dry land for closer examination. 
