Crinoidea, Pentacrininae. 57 
Holocrinus, or Pentacrinus (s. str.). Of Triassic Pentacrinidae there remain only 
Isocrinus and Balanocrinus ; and since the former is common at Cserhat, while 
the latter has not yet been recorded from this district, the obvious course is to 
refer the patina to Jsocrinus. 
To which, if any, of the species of Zsocrinus recorded from the neighbourhood 
it may belong, it is impossible to say certainly. At Cserhat occur J. candelabrum, 
I. scipio, and I. Hercuniae (?). Of these the first and last are too large except in 
quite young specimens, while the representatives of J. Hercuniae at Cserhat are 
few and doubtful. J. scipio on the other hand is by far the commonest species at 
Cserhat, and its diameter agrees better with the diameter of the stem-facet, than 
does that of any other species except J. sceptrum. There is also a sort of general 
resemblance between the smooth swollen nodals of /. scipio and the plates of this 
patina. Such an argument may not carry conviction; but it is a fact that the 
outward appearance and ornament of theca, arms, and stem of any species are 
harmonious. For all these reasons | incline to regard this patina as belonging to 
I. scipio; but, as already admitted, absolute proof is impossible with the material 
in hand. 
To whichever species this patina may belong, it is of considerable interest, 
not merely as the only patina of any crinoid whatsoever from the Trias of Bakony, 
but, so far as I can recall, the only patina of Jsocrinus known from the Trias. 
It is indeed true that both Mtnster and Lauper have described and figured a fossil 
which they regard as the patina of a Pentacrinine, the former referring a specimen 
with doubt to his Pentacrinus subcrenatus, the latter being apparently uncertain 
whether to call his specimen P. subcrenatus or P. laevigatus. Both these species, 
however, belong to Balanocrints, as already stated. But, apart from this, examin- 
ation of the original specimens and of a number of similar specimens at Munich 
and Vienna and in the British Museum (registered E 5299) has convinced me that 
the fossil is not a patina at all and that it forms no part of a Pentacrinid. 
The undoubted patina now before us is therefore the only evidence available 
as to the stage of evolution of the cup of Jsocrinus in Triassic times. It is note- 
worthy that the species had already attained the pseudo-monocyclic (or crypto-dicyclic) 
stage. That the patina does not belong to a true monocyclic crinoid is proved 
by the radial position of the angles of the pentagonal opening in the base. The 
excavation of the base is remarkable and by no means characteristic of Jsocrinus ; 
it reminds one of the base of Eucrinus. The height of the basals and their appearance 
as a closed circlet in side view are characters only found occasionally in Jsocrinus 
and then always regarded as primitive. The slight contraction of the patina towards 
its upper margin is characteristic of Holocrinus, but not of Jsocrinus. The flatness 
of the upper surface and the horizontal extension of the muscle-plates remind one 
of the Encrinidae rather than the Pentacrininae. 
In short, the patina, though with but little doubt belonging to a genus of 
Pentacrininae, still presents features reminiscent of the earlier Pentacrinidae and 
their probable ancestors the Encrinidae. 
