208 FIELD CoLUMBIAN MusEUM—GEOLOGY, VOL. I. 
During middle Upper Cretaceous times the genus continued its 
eastward migration. From India two or three of the primitive types 
are reported. From the Pacific coast of North America one species 
which is very closely allied to the early forms has been discovered. 
During middle Upper Cretaceous times came the introduction of the 
waters of the great North American epicontinental sea, and with the 
waters of this sea came in some of the primitive species from the 
Western or Eastern waters. And here as in the epicontinental sea 
of Europe conditions favorable to development were found. Bath- 
mism here also found a strong ally in environment, and the result 
was the production of thirteen or fourteen new species. But differ- 
entiation of structure was of a greater degree. The development was 
more accelerated and the changes more marked. The individual 
grew to much larger size; nodes were developed where ribs only had © 
existed; the sutures became more complex and the form more globu- 
lar. 
One remarkable fact in connection with the development of the 
genus Scaphites is that its greatest development in both Europe and 
America took place in a region lying between parallels 40° and 
50° of latitude. This may be only a coincidence, or it may be that 
when the paleontology of the now unknown regions is thoroughly 
worked out the present conditions will be found to be only apparent 
and not the real ones. If neither of these assumptions be correct 
the explanation may be found to le in the similarity of environ- 
ments. 
The following is the distribution of the species of the genus 
Scaphites. In Europe, S. wgualis, S. obliquus, S. texanus, S. conrad, 
S. nicolleti, S. hippocrepis, S. hugardianus, S. tvanit, S. compressus, S. 
constrictus, S. culvieri, S. retformis, S. getnitzt, S. inlatus, S. mul- 
tinodosus, S. nodifer, S. ornatus, S. qguadrispinosus, S. tridens, S. tuber- 
culatus, S. trinodosus; India, S. equalis, S. obliquus, S. kingianus; 
North America, S. warreni, S. conradi (3 varieties), S. larveformis, 
S. vermiformis, S. texanus, S. nodosus (3 varieties), S. mullanus, S. sub- 
globosus, S. nicollett, S. cheyennensis, S. abyssinus, S. tris, S. mandanen- 
sis, S. hippocrepts, S. culviert, S. quatsinensis, S. reniformis, S. semt- 
costatus, S. vermiculus, S. verrucosus, S. comprimus. 
ONTOGENY, PHYLOGENY AND PALEONTOGENY. No description of the > 
ontogeny or phylogeny of the genus Scaphites has as yet been pub- 
lished. As the adult forms of the majority of the species show evi- 
dences of a degenerative character, it was supposed that the genus 
was an abnormal type, and further that the individual did not per- 
