Page:American Seashells (1954).djvu/586

Pompano Beach, Florida. It is a moderately common, fairly shallow-water species. Octopus joubini Robson Joubin's Octopus Figure lood Southern half of Florida, and the West Indies. A small species with a length, including the longest arm, of from 4 to 6, rarely 7 inches. The arms are short, with a mantle-arm index of about 40 to 50. Ligula-index about 6 to 7. Gill plates 5 or 6 usually. Skin smoothish, except for little pimples at scattered intervals. In this species, the longest arm is only 2 or 3 times the mantle-length, while in O. briareus the longest arm is 5 or 6 times as long as the mantle. Eggs large, amber-colored, and about 7 to 10 mm. in length. Occasionally cast ashore in fair numbers on the west coast of Florida. O. 77ter cat oris Adam 1937 is the same. Formerly placed in the genus Paroctopus which is now considered of no value. Octopus hongkongensis Hoyle Common Pacific Octopus Figure loof Alaska to Lower California. Japan to south China. Length, including longest arm, ^ to 3 feet (possibly with a radial spread of nearly 28 feet in Alaskan waters). Skin in preserved specimens covered everywhere by numerous small, pimple-like tubercles with star-shaped bases, and by many heavy, much interrupted, longitudinal wrinkles. Above each eye there is a rather small, conical wart and with a very large, pinnacle-like protuberance behind it. Ligula index 4 to 7. The web between the second and third arms usually extends out to a quarter of the arm's length. Else- where the webs are shorter. The commonest littoral Octopus on the Pacific Coast found from shore to 100 fathoms. This is O. punctatns Gabb. O. calif ornicus Berry, an off-shore species, has a large lingula with an index of 14 to 17. The skin in preserved material is covered with numerous, large stellate warts. The Californian Deep-water Octopus. Octopus bi?naculatus Verrill Two-spotted Octopus Los Angeles, California, to Lower California. Total length ^ to 2 feet. Characterized by a large, distinct, round, dark spot in front of each eye near the base of each third arm. Eggs small, 1.8 to 4.0 mm. in length with long stalks, attached in festoons. Mantle-arm index usually 22, but ranging from 14 to 29. Ligula-index 2.0, not significant in separating this species from bimaculoides. Fairly common. Lives in the lower part of the intertidal zone down to several feet where there is rock bottom.