part 1 .] Feistmantel: Cretaceous Gems Omphalia near Nameho Lake. 23 
As to the systematical place, it seems that Omphalia is mostly related with the Turri- 
tellidce, although it presents also some similarity with the Melanidce, and Dr. Stoliczka 1. c. 
p. 211 (1867) considers it as a truly intermediate form between these two families, although 
he describes it at the beginning of the Turritellidce. 
The difference from Cerithium is established by the form of the aperture and the com¬ 
plete want of any canal to the aperture. 
In Leonhard and Bronn N. Jalirb. (1853) p. 636, a relation with Nerinea is mentioned 
as possible. But N’erinea has such a constant appeai'ance in the faults on the columella and 
in the more rhomboidal aperture, that forms of it can scarcely be mistaken. 
Also in comparison with Turritella there are differences enough. The shell of Turri- 
tella is always higher and more accumulate, thinner, has no real columella and an emargina- 
tion in the exterior lip is not constant, and when present, always shallower and the striae of 
growth therefore are never so waved. 
As to the “ conditions of living” of the Omphalia, Dr. Stoliczka already, in his revision 
of the Gosau Gasteropoda (1. c., p. 15), stated that the Omphalia in the Alps are characteristic 
of coal-hearing strata,—and he concludes that they appear to be inhabitants of brackish 
or fresh water (Pal. Ind. 1. e., p. 211), or at least more littoral (Revision 1. c., p. 15), by which 
the construction and structure of the shell is well explained. 
The genus Omphalia, Zek., is at present with certainty known mostly only from cre¬ 
taceous rocks : from Aptien, Oenomanien, and Gosau. 
A representative, as the oldest, is known from Wealden. In the Gosau, Zekeli de¬ 
scribed nine species, which Dr. Stoliczka reduced to four, but there are to be added still three 
of D’Orbigny’s Turritella, i. e., Turritella Ben'auxiana, T. llequieniana, and Turr. 
Bauga* further Coquand’s species of Cassiope are to be placed here. Three species are 
described by M. Dreseher (1. c.), but all distinct species are cretaceous. 
Our species is very well marked and different from the others known, so that I will de¬ 
scribe it as follows: 
Omphalia Teotteei, Fstrn. PI. I, f. 1—4. 
Testa conica turrita, oblonga, umbilicata apieem versus attenuata, hoc modo lateribus 
paulo ineurvata ; anfractibus septem et plurihus ; omnibus duas tantum costas distinc- 
tissimas continentibus, ultimo in solum tertia costa apparente; costis anfractorum et 
spatiis inter eos differenter ( undulatim ) striatis; apertura allonge rotunda, columella 
glabra. 
Measurements of the specimens. 
a .—'Specimen fig. 1 : 
Spiral angle, apical portion 
... 46° 
apertural portion ... 
... 30° 
Sutural angle 
... 108° 
Total height... 
46 mm. 
Height of the last whorl 
... 16 mm. 
Height of last whorl to total of shell (taken 100) 
"3 5 
' lOO 
Breadth (below) 
... 26 mm. 
In his Cretae. Gasteropoda of S. India Dr, Stoliczka considers this species again as Turritella. 
