4 PROCEEDINGS OF THE CALIFORNIA 



when adult provided with about twelve threads, stronglj- marked and dis- 

 posed in pairs. These stop just within the margin of the outer lip, which 

 is crenulated. On the fourth whorl there are about ten costte, which pass 

 the periphery, but are obsolete just beyond it. The canal is often of a 

 lighter brown than the rest. The ridges are slightly thickened on the costfe, 

 and on the last whorl are about twelve in number, with a few intercalary 

 threads. An adult measures 0.82 iu. long; 0.35 in. greatest width; canal 0.14 

 in.; canal and aperture 0.37 in.; remainder of spire 0.4-5 in. 



This rather common little shell is rare iu a perfect condition, but may be 

 obtained in a worn and rolled condition on the beaches without much trouble, 

 especially at Monterey. It is familiar to all West Coast couchologists. The 

 only characters common to it and F. geniculus, so far as the latter exhibits 

 any, are those of sculpture, which are also common to nearly all the species 

 of the Colus group and those related to them. It has been often considered as 

 a variety, or the young of the next species, from comparison of rolled speci- 

 mens. When perfect, no such confusion is Hkely. As both have been con- 

 founded together, and with ambustus as well as the apocryphal geniculus, it is 

 difficult to assert the synonymy. To some part of this omnium cjatherum Dr. 

 Carpenter has compared the Fvsus clavatus, Brocchi, a Calabrian mioceue fos- 

 sil, an inch wide and three inches long. From the descriptions of Deshayes 

 and Philippi no necessity for such allocation appears. It is in the highest 

 degree improbable that F. clavatus is closely related to any Californian species, 

 other than s^enerieally. 



Fusos KoBELTi, Dall. n. s. 



Fusus ambustus + geniculus (pars) of Californian authors. 



Habitat, Monterey to San Diego. 



Shell elegantly and regularly fusiform, of seven or eight whorls, sculptured 

 with revolving Hues and transverse costae. In young specimens the whorls 

 are somewhat rounded, in the adnlt elongated. Epidermis in perfect speci- 

 mens dark ashy or greenish olivaceous, rising in crowded lamelL-e and ob- 

 scuring the coloration. This varies, however, with age and habitat. Apex 

 acute, the second and third whorls hardly larger than the embryo. Color 

 whitish, the alternate revolving ridges of a dark brown, which occasionally 

 extends to all the ridges. These ridges do not lose their color iu passing over 

 the costae, except where worn off by rolling on the beach. Except on the 

 earlier whorls the ridges do not show any tendency to enlarge in passing over 

 the costre. On the posterior edge of the whorls the shell is appressed on the 

 suture, and the ridges here are inconspicuous, in most specimens, compared 

 with those on the body of the whorl. These ridges, moreover, bear the char- 

 acter of threads, the interspaces not being channelled as in F. Harfordi and 

 luteopictus. In the most perfect specimen, on the last whorl there are twenty- 

 two brown ridges and as many more intercalary, of the same color as the 

 shell. In melanitic specimens all may be tinged brown. On the antepenult- 

 imate whorl between the sutures there are about six main ridges and eight 

 intercalary. The costtB are rounded and prominent only on the earlier 

 whorls, but they remain on the last whorl in a flattened condition, but ex- 



