142 THE VOYAGE OF H.M.S. CHALLENGER. 
IX.—ON THE RELATION BETWEEN THE RECENT AND THE 
FOSSIL NEOCRINOIDS. 
Our knowledge of the Crinoids of the Secondary rocks is largely due to the labours of 
d@Orbigny, Quenstedt, and de Loriol, the last of whom, having completed an elaborate 
Monograph on the Fossil Crinoids of Switzerland, is now publishing a still more extensive 
one devoted to those occurring in the Jurassic rocks of France. 
He groups the Neocrinoids into ten families— 
1. Marsupitidee. 6. Apiocrinidee. 
2. Uintacrinide. 7. Bourgueticrinide. 
3. Encrinide. 8. Holopodide. 
4. Eugeniacrinide. 9. Pentacrinide. 
5. Plicatocrinide. 10. Comatulidee. 
The first two of these, each based on a single genus, are placed provisionally among 
the Neocrinoids by de Loriol, who has transferred them from the Palzeocrinoids (= Tessellata) 
with which they were ranked by Zittel. In this step, and also in the establishment of the 
new family Bourgueticrinide for the reception of Bourgueticrinus, Rhizocrinus, and 
allied genera, I entirely agree with de Loriol; but I am not disposed to follow him and 
Zittel in the association of Hyocrinus and Plicatocrinus into one family, and prefer to 
consider the former genus as the type of a new family “ Hyocrinide.” It has not yet 
been discovered in the fossil state ; and of the ten families enumerated by de Loriol, the 
first six in the above list died out at or before the close of the Secondary period ; while 
all the four others have living representatives. 
Little need be said about the extinct Neocrinoids, except that the association of the 
Cretaceous Marswpites and Uintacrinus with the Paleocrinoids, the so-called Tessellata, 
appears to me to be based on a misconception ; and that Hncrinus, as might be expected 
from its stratigraphical position, finds its nearest allies in genera of the Carboniferous 
and not of the Jurassic epoch, as will be pointed out later. 
The characters of Plicatocrinus are entirely different from those of any recent Crinoid, 
though its calyx has a singular resemblance to those of young Pentacrinide. The 
Eugeniacrinide are a less aberrant group; but though the symmetrical forms of Hugenia- 
crinus appear to have a considerable resemblance to Rhizocrinus and Bathycrinus in the 
structure of the lower part of the cup and in the distribution of the canal system, yet 
such types as Phyllocrinus and the distorted Torynocrinus are altogether different from 
any recent Crinoid. 
The Apiocrinidee, represented by some doubtful species in the Lias, flourished exten- 
