Dr. H. Trautschold—Periodical Movement of the Ocean. 487 
Although I placed G. calcaratus in 1877 as a synonym under G. 
mucronatus, I find that neither the description nor figure admit of its 
being so disposed of, and I therefore give it on M‘Coy’s authority. 
Valerian von Moller says of Griffithides calcaratus, ‘“‘M‘Coy only 
figures the cephalothorax, it is nearly related to P. globiceps, Phill., 
but is distinguished from this species by the very inferior size of the 
glabella, and by the long flattened cheek spines; from another 
Trilobite, P. longiceps, Portl. (= G. longispinus, Portl.), with which 
it is also nearly connected, but from which it differs in its very 
narrow glabella and the wide flattened border around the pygidium.” 
GRIFFITHIDES morIcEPS, H. Woodw. sp. nov. 
Head-shield semicircular, 22 mm. long and 80 mm. broad ; glabella 
elevated, very gibbous and obtuse in front, and twice as wide at the 
anterior border as at the neck furrow; basal lobe small, rounded ; 
surface of glabella and free-cheeks thickly covered with large round 
granulations ; facial suture running very close around the glabella ; 
free-cheeks hatchet-shaped, central ornamented part raised and bearing 
the small smooth reniform eyes close to the basal lobe; border of 
cheeks deeply furrowed and smooth, with a raised margin having a 
rounded rim ; neck-lobe narrow, smooth, flattened and separated by 
a rather strongly marked neck-furrow, which is continued and unites 
with the furrow surrounding the free-cheeks, forming somewhat 
blunt angles to the head-shield. 
Formation.—Carboniferous Limestone, 
Locality.x—Settle, Yorkshire. 
All the specimens of G. moriceps which I have seen are preserved 
in the Woodwardian Museum at Cambridge. 
EXPLANATION OF PLATE XII. 
Fic. 1. Restored outline figure of Grifithides seminiferus, Phil. sp., enlarged twice 
nat. size. 
», la. Hypostome of same. 
», 2- Restored outline figure of Grifithides globiceps, Phillips, sp. enlarged one 
and a half times nat size. 
5, 8. Restored outline figure of Grifithides longiceps, Portl., enlarged three and 
a half times nat. size. 
», 4. Restored outline figure of Grifithides acanthiceps, enlarged one and a half 
times nat. size. H. Woodw. f 
,, 6. Restored outline figure of Griffithides longispinus, Portlock, enlarged twice 
nat. size. 
(Lo be continued.) 
IJ].—A Frew Worps Concerning THE Prriop1caAL MovEMENT OF 
THE OCEAN. 
By Dr. Hi. TRAUTSCHOLD, 
of the Petrovsky Academy, Moscow, Russia. 
INCE geology entered the order of exact sciences, it has been 
S acknowledged by all those, who thoroughly studied it, that 
the history of the earth is to be divided into three great periods, 
which have been called, after the faunas they contain, Paleozoic, 
Mesozoic and Cainozoic. Indeed it could not escape the eye of the 
paleontologist, that between the marine faunas of the Permian period 
