488 Avierican Seashells 



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. 



