. Annual report of the regents of the university of the state of New York on the condition of the State Cabinet of Natural History and the historical and antiquarian collection annexed thereto. rotund and broaderon the dorsuc, with a larger umbilicus, than G. rotatorius, with which it is as-sociated. The species appears to be variable in some of its characters, and we find twosomewhat constant varieties. The difference in proportional size of umbilicfts isaccompanied by other characteristics. In a specimen with a large umbilicus, thedorsal lobe has the form described, and the extremity does no
. Annual report of the regents of the university of the state of New York on the condition of the State Cabinet of Natural History and the historical and antiquarian collection annexed thereto. rotund and broaderon the dorsuc, with a larger umbilicus, than G. rotatorius, with which it is as-sociated. The species appears to be variable in some of its characters, and we find twosomewhat constant varieties. The difference in proportional size of umbilicfts isaccompanied by other characteristics. In a specimen with a large umbilicus, thedorsal lobe has the form described, and the extremity does not reach so low asthe arch of the saddle in the second septum behind; while in specimens with asmall umbilicus, the sides of the dorsal lobes are quite parallel, and the peripheryof the shell is marked by a pair of continuous grdoves parallel with the sides ofthese lobes; and the extremities reach beyond the arch of the saddle in the secondseptum behind. This feature indicates a closer arrangement of the septa through-out, which does not appear to be due to age. For this variety I would propose the name of G, paralhla, from the linealgrooves on the periphery bordering the dorsal
Size: 1493px × 1675px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, booksubjectscience, bookyear1853
