126 



or less acutelj^ conical, with obliquely flattened sides, the fifth and sixth 

 concave above and swollen below into a prominent, narrowly rounded, 

 nodulous, spiral ridge. Body whorl encircled in the middle by the same 

 spiral ridge, broadly and concavely excavated above, and narrowing rather 

 abruptly below into a stout, straight beak, whose length is nearly equal 

 to that of the spire. Aperture ovately sub-triangular, angular or sub- 

 angular near the middle on the outer and nearly straight on the colum- 

 ellar side; outer lip formed of a single flatly expanded varix, which is 

 ribbed externally and crenulated within; inner lip encrusted, slightly 

 convex above and straightor below, beak channelled, the channel open 

 throughout its entire length ; columella with four inconspicuous teeth or 

 flattened tubercles at its upper end, and with three plaits or laminar teeth 

 below. The teeth on the upper part of the columella are placed close 

 together, the plaits or laminar teeth at its lower or anterior end, on the 

 contrary, are comj^aratively far aj)art from each other. The first, or pos- 

 terior plait, which is transverse and moderately prominent, is situated 

 about the middle of the aperture, exactly opposite the angle of the outer 

 lip ; the second is rather more than a line in distance from the first ; the 

 position of the third, or anterior one, is not very clearly shewn, but it 

 appears to be placed very near to the commencement of the canal. All 

 the teeth and plaits are small, and situated go far back in the aperture 

 that they can scarcely be seen, except in specimens in which part of the 

 outer lip is broken away. 



The entire surface is marked by numerous, simple, rounded, revolving 

 raised lines, which are placed at vaj-ying distances apart, but which are 

 always narrower than the flattened spaces between them. At least 

 twenty-one of these revolving lines can be counted on the bod}^ whorl, and 

 those below the central ridge are much larger than those above it. The 

 spiral ridge or blunt keel, which encircles nearly the whole of the shell, 

 is crossed, also, by distant, transverse, rounded, raised folds and corres- 

 ponding depressions, but the folds are obsolete, or nearly so, both above 

 and below the ridge, where the shell is simply striated across. The 

 whorls of the spire, accordingly, are coronated below, and the body 

 whorl bears about fourteen conspicuous, and transversely elongated but 

 somewhat rounded nodes on its central blunt keel. 



Two specimens of this species were collected by Mr. Eichardson in 18'72, 

 one from the Nanaimo River, V. I., two and a half miles up, the other 

 from Protection Island, both in Division A. These have been figured and 

 briefly described in the " Report of Progress " for 1873-74, under the name 



