. The Conchologists' exchange. Mollusks. 132 THE NAUTILUS. between grooves, which are eight or ten in number, the nodules fading away as the canal is reached, but in the type specimen the nodules are present over the whole of the smooth part without, however, any grooves between. Anal notch rather deep, and marking the spire. with its former positions; outer lip thin, pillar lip straight with a very slight twist; aperture straight above, widening near the base. Length 20 mm., max. diameter 12 mm. Locality : Shoal Creek, Walton county, Florida. Remarks : Tliis shell bears a close resemblance to
. The Conchologists' exchange. Mollusks. 132 THE NAUTILUS. between grooves, which are eight or ten in number, the nodules fading away as the canal is reached, but in the type specimen the nodules are present over the whole of the smooth part without, however, any grooves between. Anal notch rather deep, and marking the spire. with its former positions; outer lip thin, pillar lip straight with a very slight twist; aperture straight above, widening near the base. Length 20 mm., max. diameter 12 mm. Locality : Shoal Creek, Walton county, Florida. Remarks : Tliis shell bears a close resemblance to Conns puncti- culatus Hwass, and is doubtless an ancesti-al form, thus adding an- other link to the chain of evidence of a connection between the At- lantic and Pacific Oceans during Tertiary times. This species has been in my possession for many years and until lately was not known to me from any other locality, but on looking over some specimens of fossils from the Number 2 well of the Mobile Oil Co., bored near Mobile, Alabama, I found two or three speci- mens of it, and from its position over three hundred feet above the Oak Grove (Fla.) horizon in this well, it would seem to indicate that this deposit on Shoal Creek is much younger than the Oak Grove beds. The assignment of these beds to the Oligocene must, in the writer's opinion, be better substantiated than at present. There are so few species common to the " Chipola" of Dall and the Vicksburg formation, it would seem better to confine the use of the term " Olig- ocene " to the latter, which is in accordance with Conrad's original diagnosis, and put the Chipola, Shoal Creek and Chattahoochie beds into one formation, calling them all Miocene, and if this should eventually be done, then this formation should bear the name its discoverer, D. W. Langdon, Jr., gave it of " ; D. G. Harris figures a Conns functiculatus Hwass from the Gal- veston deep well. It is probably the same sp
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectmollusks, bookyear188
