Page:American Seashells (1954).djvu/256

206 M. erinaceoides rhyssus Dall is similar to trialatiis, but with scaly fim- briations all over, sometimes with numerous, rather strong spiral cords, and grayish white in color. Southern CaHfornia, south. Uncommon offshore. Subgenus Maxwellia Baily 1950 Murex gejimm Sowerby Gem Murex Plate 246 Santa Barbara, CaHfornia, to Lower California. I to I % inches in length, moderately high-spired, with 6 varices per whorl. The varices are swollen, roundish and smooth and connect with each other in the middle area of the whorl, but in the area of the suture, and again near the base of the shell, the varix is thin, elevated and curled back and may bear one or several small spines. There are several spiral low cords colored blackish blue which are more obvious on the middle or smoother part of the whorl. The spire appears to have squarish pits crudely dug out. Very com- mon along rocky areas under protective rubble and masses of worm tubes. Murex santarosana Dall Santa Rosa Murex Figure 45d Santa Barbara Islands to Lower California. I /4 inches in length, spire low, and with 6 curled-back, spined varices per whorl. Anterior surface of varices strongly fimbriated. Narrow intervarical space smooth. Color brownish white. Uncommon to rare on gravel bottom just offshore to 30 fathoms. Do not confuse with the common gemma. Murex festivus Hinds Festive Murex Plate 24I Morro Bay, California, to Lower California. I /4 to 2 inches in length, spire high, 3 varices per whorl. Color brownish cream with numerous fine, dark spiral lines. V^arix, with its thin, fimbriated surface, curled backwards. One very large, rounded nodule between varices. Very common on rocks or mud flats and down to 75 fathoms. Genus Boreotrophon Fischer 1884 Boreotropho7i clathratus Linne Clathrate Trophon Arctic Seas to Maine. I to 2 inches in length, with rounded whorls, slightly flaring lip, and numerous axial, foliated ribs. Chalk-white in color. There are several forms 1