68 
HAYDEN : GEOLOGY OF SPITl. 
few, however, were determinable : these were derived from two 
horizons — 
(a) six inches above the top of the bed with Rhynchonella 
griesbachi \ and 
(3) middle of the nodular limestone, i.e., about 30 feet above 
the horizon of Rhynchonella griesbachi. 
The specimens from {a) include — 
Tiro lit es n. sp. ^ 
(?) Dinarites sp. ind. 
The first of these forms had hitherto been found only in the lower 
trias, having been obtained from the Hedenstraemia beds near Muth. 
Horizon [b) yielded — 
Ceratites n. sp., identical with a form previously obtained from 
the Hedenstraemia beds at Muth ; and 
Nannites n. sp. ind. 
With regard to these discoveries it will be advisable to quote Dr. 
von Krafft's own words, from a letter written by him to the present 
writer, shortly before liis death: " It is clear that the horizon of Rhyn- 
chonella griesbachi^ looked upon by Diener, Griesbach, Bittner and 
myself as lower muschelkalk, must be included in the lower trias, and 
so must at least half of the nodular limestone. The genus Tirohtes 
is in Europe known from the lower trias only : the species from the 
base of the nodular limestone is, moreover, identical with a type from 
the ' Subrobustus beds ' (Diener). The occurrence of C^r^^^^V^J n. sp. 
in the middle of the nodular limestone only corroborates this con- 
clusion. The boundary between the lower trias and the muschelkalk 
is therefore much more accurately fixed than it was before, and must 
lie either within the nodular limestone or at the base of the beds with 
Spiriferina stracheyi. The former is, I think, more probable, be- 
cause I remember having found lower muschelkalk types in the top- 
most beds of the nodular limestone." 
* A description of this species, which he named T, injucundus, has been left 
among Dr. von Krafft's descriptions of lower trias ammonites, which it is hoped 
will be published shortly. 
( 68 ) 
