Page:American Seashells (1954).djvu/577

Rh The rather fragile, white shell is a chambered cone coiled in a flat spiral, usually less than i inch in diameter and with the coils not in contact. Each small chamber in the shell is divided from its neighbor by a nacreous-white,

Figure 98. The white, inch-long shells (a and b) of Spin/la spirilla Linne are commonly washed ashore on southern beaches, but the squid-like animal (c) lives at great depths and is very seldom captured alive. concave, fragile septum or wall. There is a small siphonal tube running back into the shell and piercing the septa. These shells are cast up on the beaches quite commonly. The body is short and cylindrical, and surrounds the shell almost completely except for two small areas. The 8 sessile arms and 2 pe- dunculated tentacular arms are very short. Myopsid Squid — transparent cornea over eyes; pupils crescent-shaped Family SEPIOLIDAE Genus Rossia Owen 1828 Short, "tubby" animals whose bodies are rounded at the end. The man- tle edge is free all around. 8 arms short with 2 to 4 rows of spherical suckers which have smooth, horny rims. The two tentacular arms can be almost entirely withdrawn. The internal pen is slender, lanceolate and very thin and delicate. The rather large, semi-circular fins are on the middle of the sides of the body. Eye with small eyelid on the lower side, none above. No sulcus or notch on front of the eye. Rossia pacifica Berry Pacific Bob-tailed Squid Alaska to San Diego, California. Total length, not including the tentacles, 3 to 4 inches. Body smooth, mantle flattened above and below, rounded behind. Fins large, semi-circular or subcordate, with a free anterior lobe, their attachment more or less obhque to the general plane of the body. Color in life unknown; in alcohol, reduced to brownish buff, heavily spotted above and in less degree below with pur- plish chromatophore dots, which extend even over the fins, although fewer on under surfaces and margins. This is the only Rossia recorded on the Pacific Coast, and it is rather abundant from 9 to 300 fathoms.