. First[-fourth] annual report of the Geological survey of Texas, 1889[-1892] Edwin T. Dumble, state geologist. re of a specimen (Figs. 30, 31) fromDr. Newberrys collection, reported to have come from Miami County, Illinois,is of an entirely different appearance from the later stages, with an almostround whorl, sutures nearly straight or with only a slight abdominal saddle,shell smooth and umbilical perforation large, showing that they were truecyrtoceratites throughout the first whorl, which was not completed until theshell had reached a considerable size. The amount of involution of the youn
. First[-fourth] annual report of the Geological survey of Texas, 1889[-1892] Edwin T. Dumble, state geologist. re of a specimen (Figs. 30, 31) fromDr. Newberrys collection, reported to have come from Miami County, Illinois,is of an entirely different appearance from the later stages, with an almostround whorl, sutures nearly straight or with only a slight abdominal saddle,shell smooth and umbilical perforation large, showing that they were truecyrtoceratites throughout the first whorl, which was not completed until theshell had reached a considerable size. The amount of involution of the youngerwhorls by the living chamber is exaggerated in the side view of this specimen(Fig. 31), and is better indicated in the front view of the same. The resem-blance of the young whorl in outline to that of the genus Temnocheilus canbe readily seen in the last figure in which the front view of the first part ofthe second whorl is shown. On this second whorl a single row of tuberclesappears on either side, and theee complete the resemblance to Temnocheilus. 336 GEOLOGICAL SURVEY OF TEXAS. .; v, \ ?:;.;%.
Size: 1013px × 2466px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., boo, bookcentury1800, booksubjectgeology, booksubjectpaleontology
