. West American shells; a description in familiar terms of the principal marine, fresh water and land mollusks of the United States found west of the Rocky Mountains, including those of British Columbia and Alaska ... inespecimen was dredged by Mr. H. N. Lowe, off SanPedro, in 10 fathoms of water. Miirex circumtextus, Stearns, theCircled Murex, Figure 196, (Ocinebracircumtexta), has a rather heavyshell, many low varices, very deep anddistinct spiral grooves which give theouter lip a scalloped ai)pearance. Itis of a reddish color within, but ex- Fig. i96 ternally it is whitish, with brown spots
. West American shells; a description in familiar terms of the principal marine, fresh water and land mollusks of the United States found west of the Rocky Mountains, including those of British Columbia and Alaska ... inespecimen was dredged by Mr. H. N. Lowe, off SanPedro, in 10 fathoms of water. Miirex circumtextus, Stearns, theCircled Murex, Figure 196, (Ocinebracircumtexta), has a rather heavyshell, many low varices, very deep anddistinct spiral grooves which give theouter lip a scalloped ai)pearance. Itis of a reddish color within, but ex- Fig. i96 ternally it is whitish, with brown spots arrangedin a spiral. Murex festivus, Hds., the Fes-tive Murex, (Pteronotus festi-vus), is shown in Figure 197. Ihave gathered fine specimens ofthis grand species at San Pedro,when the tide was low, by goingamong the piles of the wharvesto which these and other speciesof mollusks were clinging. Theshell is plainly marked by threereflexed frills on each whorl, al-ternating with rounded perfect specimens there arenumerous fine spiral lines of sculpturing, whichare often covered with foreign substances. Thecanal is completely closed, forming a tube, whichis reflexed near its extremity. The color is white. Fig. 197 1P3 WEST AMERICAN SHELLS or gray, though the outside is often veiy picture represents a good sized specimen,though it sometimes grows considerably species loves warm water too well to migratefar to the north. Figure 198 introduces us toanother southern shell, Murexnuttdllii, Conr., Nuttalls Mu-rex, (Cerostoma nuttallii). Ifyou examine a full grown shellof this species you will find asharp tooth, or horn, near thebase of the outer lip. Someyoung specimens have no horn,and they have an open canalinstead of a closed one. Al-lowance must always be madefor the age and development Fig. i9s of the specimen. The shell of this species is abouttwo inches long, and is of a dingy white color,somewhat marked with brown. On each whorl arethree distinct v
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmollusks, bookyear190
