 | Academy of Natural Sciences of Philadelphia - 1858 - 280 sider
...the aperture into an acute point. The aperture of this curious shell resembles that of H. faliyiata, Say. It is readily distinguished from that and all...narrowing beyond the second whorl, with the peculiar grooTe Tieible in all the whorls ot'lhe umbilicus, of tli* same character as that noticed by Say in... | |
 | 1863 - 720 sider
...Since that time another specimen has been received by him from an undoubted Texan locality. . Remarks. The aperture of this curious shell resembles that...the second whorl, with the peculiar groove visible iu all the whorls of the umbilicus, of the same character as that noticed by Say in auriculata, though... | |
 | United States National Museum - 1885 - 984 sider
...lesser 9mrn ; height, 4""". The aperture of this curious shell (tholus) resembles that of P. fastigans, Say. It is readily distinguished from that and all...noticed by Say in auriculata, though deeper. The name tholus is derived from the resemblance of the slightly raised, rounded spire to a low dome. Jaw with... | |
 | United States National Museum - 1885 - 594 sider
...! .« t .. ' r l>iV*r v4 : • •. • fin . <i •: • • *• i li. 't UMI v .!•»'*.*' gam, Say. It is readily distinguished from that and all...noticed by Say in auriculata, though deeper. The name tholus is derived from the resemblance of the slightly raised, rounded spire to a low dome. Jaw with... | |
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Say. It is readily distinguished from that and all other described species by the umbilicus, broad at the commencement and rapidly narrowing beyond the second whorl, with the peculiar groove visible in all the whorls of the umbilicus, of the same character... 