Review of Recent Qeologicul Literatuve. 331 
near New Ulm, Mian., were found to be well charged with the same or- 
ganisms. Their plentiful occurrence in the till at Chicago leads to the 
belief that the Cretaceous ocean, which is known by remnants of its 
deposits to have reached across nearly or quite the entire state of 
Minnesota, also extended east to the region about the northern part of 
lake Michigan, whence the Cretaceous Foraminifera were probably sup- 
plied to the Illinois glacial drift. 
Sponges, Graptolites and Corals from the Lower Silurian of Minne- 
sota. By N. H. Winchell and C. Schuchert. pp. 55-9;"), with Plates F 
and G, and seven figures in the text, forming chapter in in the volume 
before noted; June G", 1893. The species described with figures in this 
paper are Receptaculites oweni Hall, Isehadites ioxvensis Owen (sp.), 
Lepidolites dickltauti Ulrich, Anomalospongia reticulata Ulrich, Rauf- 
fella filosaXJlricb, R. palmipes Ulrich, Cylindroccelia mi nne sot ens is 
Ulrich, Heterospnngia subramosa Ulrich, Hindia parva Ulrich, Solen- 
opora compacta Billings, Diplograptus pristis (Hisinger) Hall, D. putil- 
lus Hall, Climacograptus typicalis Hall, Lichenaria typa (gen. et sp. 
nov.l W. and S., L. minor (n. sp.) Ulrich, Columnar ia (?) halli Nichol- 
son, Streptelasmaprofundum (Conrad ms.) Owen, S.parasiiicum ( n. sp.) 
Ulrich, S. corniculum Hall, S. breve (n. sp.) Ulrich, S. rusticum Billings, 
Protarsea vetusta Hall (sp. ), and Aulopora ( ?) trentonensis (n. sp.) W. 
and S. These fossils occur in the Trenton, Galena, and Hudson River 
formations of southeastern Minnesota, beyond which their known geo- 
graphic and geologic range in the case of species found elsewhere is also 
noted. 
On Lower Silurian Bryozoa of Minnesota. By E. O. Ulrich. pp. 
96-332, with 28 plates, and figures 8-20 in the text, forming chapter iv 
in the volume before noted; Jan. 15, 1893. This elaborate monograph 
comprises descriptions of 156 species of Bryozoa, referred to 49 genera. 
Seventy-five of the species and seven genera are new, being here de- 
scribed for the first time. Many others are also of Mr. Ulrich's publica- 
tion, but in previous reports or journals, notably the Journal of the 
Cincinnati Society of Natural History. They are found in great 
abundance in the Trenton and Galena shales and limestones from 
Minneapolis and St. Paul southward through the Lower Silurian por- 
tion of the state. 
"It is a singular fact,*' remarks the author in writing of the geologic 
distribution of this faunal class, ''that no remains whatever of Bryozoa 
are known from rocks of earlier date than the Chazy limestone of the 
Lower Silurian system. Here the class suddenly leaps into a promi- 
nence, not only in the way of individual representation, but in the mat- 
ter of diversity of structure, that is both surprising and difficult of ex- 
planation. Nor was it, as might be expected, the simpler types that 
prevailed here. On the contrary, it is the more complex types like the 
Trepostomata and Cryptostomata that are the most abundant and di- 
verse in their development. What may be even more surprising is that 
