Conus waltonensis                 (Aldrich, 1903)

 

 

Shell medium in size, substance rather thin ; spire elevated, with nine whorls, including the apex, which is rather sharp, profile of spire slightly broken by a shoulder just above the suture on each whorl, the suture impressed, each whorl of the spire concave, and marked by numerous curved lines; periphery sharp; body whorl below the keel in some specimens over one-half smooth, then below this bearing two or three spirals of evenly-spaced nodules without any grooves between, gradually changing to rows of nodules on bands 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 wilhout, 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 (1).

 

Length 20 mm., max. diameter 12 mm.

Locality : Shoal Creek, Walt on county, Florida.

 

Remarks : This shell bears a close resemblance to Conus puncticulatus Hwass, and is doubtless an ancestral form, thus adding an­other link to the chain of evidence of a connection between the At­lantic and Pacific Oceans during Tertiary times (1).

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 speci­mens 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 Civek 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 " Olig­ocene " 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 " Chattahoochie" (1).

D. G. Harris figures a Conus puncticulatus Hwass from the Galveston deep well. It is probably the same species as the one herein described. The pustules on the living shell appear to be in the grooves while on the fossil form they are between them (1).

 

 

 

 

 

Conus waltonensis (1)

mm. 20 x 12

 

Conus waltonensis

Shoal River Fm.

Walton County

mm. 21,3 x 13,3

[AZFC 552-01]

Conus puncticulatus  Hwass in Bruguière, 1792 Primary Type Image                   Conus puncticulatus  Hwass in Bruguière, 1792 Primary Type Image

Conus puncticulatus

Lectotype MHNG 1107/40

mm. 27 x 17

Colon - Panama

 

 

 

 


Conus waltonensis anodosus (Gardner, 1937)

 

 

Shell of moderate size, of rather heavy texture and inclined to be stout; relative height of spire ranging as in C. waltonensis s. s. from less than one-fifth to onethird of the altitude of the entire shell and the apical angle from approximately 90° to 120°. Whorls 9 or 10 in the adult, closely embracing the suture line, falling a little in front of the periphery of the.preceding volution. Nucleus, small, smooth, erect, its two or three component whorls relatively high and flattened laterally (2).

Axial sculpture of conch restricted to incrementals, which are strongest upon the shoulders of the whorls of the spires. Spiral sculpture confined to the anterior half of the body, 6 to 10 fillets or ridges separated by narrower channels usually developed, exclusive of the half dozen crowded lirae upon the anterior canal. Sutures strongly impressed. Aperture rather wide, the margins subparallel. Outer lip deeply emarginate at the shoulder for the protrusion of the posterior siphon. Labrum very thin and parallel to the inner lip. Aperture slightly expanded at the anterior canal, which is broadly and very feebly emarginate (2).

 

Dimensions: Maximum height, 20.0±millimeters; altitude of spire, 3.5± millimeters; maximum diameter, 12.0 millimeters.

Holotype: U. S. Nat. Mus. No. 351122.

Type locality: No. 3856, 5 to 6 miles west-northwest of Mossyhead, Walton County, Fla.

 

The subspecies differs most radically from C. waltonensis s. s. in the nondevelopment of spiral rows of pustules upon the body whorl. In some specimens a few rows are present on the medial portion near the aperture, but commonly they are absent altogether. Transitional forms are less abundant than might be expected in two races, both so prolific within the same area. The subspecies runs a little larger possibly than the species in the strict sense, although the relation is apparently not that of young and adult, since young forms occur with no trace of a nodose sculpture developed upon them, whereas adults, such as Mr. Aldrich's type, occur with nodules from the periphery of the ultima to the anterior canal. The thinness of the outer lip seems to have rendered the form peculiarly susceptible to injury, and repairs have been made on a large proportion of the shells collected (2).

 

Occurrence: Shoal River formation, localities 3856pr, 2645P, 3731a, 5080C, 5184a, 5195P, 3742a (2).

 

Conus waltonensis anodosus (2)

Plate XLIII, figure 15

mm. 20 x 12

 

Conus waltonensis anodosus (1)

MR 4127-537

mm. 22

 

 

 

 


Conus waltonensis blountensis (Mansfield, 1935)

 

Shell small, ruther stout with 7 or 8 whorls in all. Spire turrited, evenly and broadly conic and constitutes about one-fourth of shell length. Spire whorls carinated at the lower shoulder and depressed medially. Body whorl broad above and narrow below and sculptured, from the upper third to the siphonal fascicle, with about 10 rather wide spiral bands, which arc ornamented with a few granules. Siphonal fascicle weakly elevated and marked

with 5 or 6 closely spaced and narrow spiral bands (3).

 

The holotype (U.S.N.M.Cat.No.373119) measures: Length, 17.2 mm.; greatest diameter, 9.2 mm.; Length of spire, 5 mm.

 

Conus waltonensis blountensis, n. subsp. differs from Conus waltonensis Aldrich, a species from the Shoal River formation in having a relatively higher and more evenly conic spire; broader body whorl above and more constricted below; a stronger carina at the shoulder of the body whorl; and in the absence of granules on the upper third of the body whorl (3).

Occurrence: Upper middle Miocene, Area zone. Station 12046, Vaughan Creek, upper locality, Walton County, Fla. (type locality). Known only from the type locality (3).

 

 

 

Conus waltonensis bloutensis (3)

Plate 1, figure 9

mm. 17,2 x 9,2

 

 

 


Bibliografia Consultata

 

·        (1) - Aldrich, T. H., 1903. A new Conus from the Tertiary of Florida. The Nautilus: A Quarterly Devoted to Malacology, 16 (11 ): 131 -132

·        (3) - Mansfield, W. C., 1935. New Miocene Gastropods and Scaphopods from Alaqua Creek Valley, Florida. State of Florida, Department of Conservation, Geological Bulletin, 12: 1 -64

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