U.S. Geological Survey Professional Paper Volume 133

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1923 Excerpt: ... these are due to different stages in development the condition of the specimens does not show clearly. What seem to be the young of this species have a pointed apertural end in specimens consisting of two or three chambers only. Others seem to be rather rotund from the beginning, and it may be that these two represent different species. Polymorphina gibba occurs at the following' U. S. G. S. stations: Byram calcareous marl.--Byram, Miss., 6454 and 6455; Vicksburg, 8240; Brandon, Miss., 7389; Leaf River, Miss., 7376; Woodward, Miss., 6648; Waynesboro, Miss., 6649. Glcndon limestone.--Vicksburg, Miss., 6446; Robinson's quarry, Miss., 6548; Tiger Hill, Miss., 7735; McGowans Bridge, Ala., 6749. Typical Marianna limestone.--Oastleberry, Ala., 6732 and 6734; Perdue Hill, Ala., 6729; Millry, Ala., 6702; St. Stephens, Ala., 6710 and 6711; Fail, Ala., 7214; Heidelberg, Miss., 6645; Tallahala Road, Ala., 7375; Brandon, Miss., 7371; Calmar, Miss., 7445. Mint Spring calcareous marl member.--Vicksburg, Miss.. 6447, 6448, and 6451; Browns Cave, Miss., 7671; Boice, Miss., 6647. Red Bluff clay.--Hiwannee, Miss., 6456 and 8752; St. Stephens Bluff, Ala., 6713; Fail, Ala., 7213. Polymorphina byramensis Cushman. Plate V, figures 1-5. Polymorphina byramensis Cushman, U. S. Geol. Survey Prof. Paper 129, pp. 94,131, pi. 17, figs. 2a, 2b, 1922. Test short and broad, triangular, composed of a few chambers, usually only four, all except a final fifth chamber extending back to the base of the proloculum, forming a truncate test; chambers inflated; sutures deep and distinct; surface smooth; aperture radiate, only slightly produced. Maximum length 0.75 millimeter. This is one of the most common species in the Vicksburg, occurring at most of the stations, except in the typical Marianna...