ialontolngia ndita,

FAUNA OF KACHH (CUTCH). 167
for study. Thus Uhlig (1910, p. 264) left a Spiti form that he compared to
W aagen' s ' Stephanoceras ' maya, and two additional species ( ' M acrocephalites
' waageni and 'M.' kitchini), in the genus Macrocephalites, considering them
to be 'recticostati ' ; and it must be admitted that certain Franconian .ll!lacrocephalites
of the bathytmetus type show extremely close resemblance in their
outer whorls. While uniting with the later forms, generically, certain curvicostate
Callovian species (here referred to Kamptokephalites and Dolikephalites)
Uhlig assigned the ' geologically younger' curvicostati, including not only Grayiceras
nepalense (Gray) and Prograyiceras grayi (Spath) but also Subkossmatia
opis (Sowerby) and Idiocycloceras singularis, nov. ( = Waagen's Stephanoceras
fissum, non Sowerby sp.),
to the Hauterivian genus Simhirskites. Obviously
there is no connexion between date of existence and amount ·of peripheral
projection. Lemoine (1910, p. 20) again thought that his group II of macrocephali,
namely this same maya group (to which he again compared Waagen's
Stephanoceras semilaeve, already listed in group I), on account of its slightly
forwardly projected costation, was rather closer to Simbirskites than to Macrocephalites.
The classification of macrocephali into recticostati and curvicostati certainly
does not work in practice; Waagen's 'Stephanoceras ' lamellosum and St. subtrapezinum,
assigned one to each of these divisions, are here united specifically.
Again the recognition by later authors of a group of 'jlexicostati' was unsuccessful,
nor can the coarseness or :fineness of the ribbing be used except
in conjunction with other characters. Kamptokephalites lamellosus illustrates the
impossibility of relying on the variable course of the ribs as the sole criterion
of classification.
When comparing (1924, p. 8) Sowerby's unique holotype (PI.
XIX, figs. Sa, b) with Waagen's (slightly inaccurate) figure, I laid stress on
the difference in the course of the radial line ; but the examination of abundant
additional material has shown that the more or less apparent biconvexity
of the ribbing as well as the peripheral projection and approximation of the
ribs near the aperture are subject to considerable variability and not of J pecific
importance. The characterisation of Mr. Buckman's genus 'Macrocephaliceras'
(1923, p. 54), based on an execrable whorl-fragment, as ' flexicostate, ribs medium
size ' is not only useless but misleading.
Finally whorl-shape is so valiable individually as well as at different growthstages,
that the generic separation of the sphaeroconic forms from their compressed
allies is not natural or scientific.
Kamptokephalites was defined as 'com­
but its genotype was included by Blake (1905, PI. IV, fig. 2) in
pressed ',
the more sphaeroconic K. herveyi (Sowerby) and a comparison of the originalsshows
that it is perhaps scarcely sufficiently different to be classed even as a
variety.
Lemoine (1910, p. 17) thought it preferable to substitute for Waagcn's.
'rather too theoretical ' classification of the macrocephali an essentially practical
scheme, based mainly on external shape. It will be necessary to criticise
this classification in detail, but for the present it may suffice to state that.
Waagen'a careful grouping at least had the advantage of taking into consi-