202 WEST AMERICAN SHELLS 
purple juices of the animal. The operculum is a 
brown scale, nearly circular, and showing lines of 
growth. The color of the shell is white, and its 
common length is about an inch. 
In Figure 213 is shown the beautiful 
shell of Scala hindsu, Cpr., the White 
Ladder-shell, (Scalaria hindsi). It is 
pure white, very delicate, and is gener- 
ally less than an inch in length. The 
ig-715 whorls are very distinct, finely rounded, 
and each one is crossed by about twelve thin, sharp 
ridges. These shells are so highly prized that they 
are sometimes worn as the drops of ear-rings. 
This species is found in the south. 
Scala indianorum, Cpr., the Indians’ Ladder- 
shell, is a species found more commonly in the 
north, especially about Puget Sound. It has a 
thicker shell than the last species, more whorls, 
more varices, and less prominent sutures. 
Scala bellastriata, Cpr., the Striped Ladder- 
shell is easily identified from the fact that between 
the varices fine spiral ridges may be seen, wind- 
ing up towards the apex. The spire is short, the 
last whorl quite large, the varices very numerous, 
and the sutures so deep that they almost entirely 
separate the round whorls. Length, 15mm.; 
southern. 
Scala crebricostata, Cpr., the Close-ribbed Lad- 
der-shell. This shell has about fifteen sharp, thin. 
reflexed varices to a whorl, which form a kind of 
crown at the shoulder. It is found from Monterey 
to San Diego. 
