LIST OF BRYOZOA. 7 
Alphabetic list ofbryozoa in Rochester shale, showing range and comparative abundance — 
Continued. 
Western 
New 
York. 
Ontario. 
Osgood 
beds, 
Indiana. 
Waldron 
beds, 
Indiana. 
Monotrypa pediculata n. sp 
Nematopora minuta (Hall) 
Nieholsonella florida (Hall) 
Nieholsonella ringuebergi n. sp 
Orbignyella expansa (Ringueberg) 
Orbignyella magnopora n. sp 
Pachydictya crassa (Hall) 
Phaenopora ensiformis HalL 
Phamopora fimbriata canadensis n. var 
Phylloporina asperato-striata (Hall) 
Polypora incepta Hall 
Pseudohornera diffusa (Hail) 
Pseudohornera niagarensis (Hall) 
Ptiloporella nervata (Nicholson) 
Rhinopora curvata Ringueberg 
Rhombotrypa spinulifera n. sp 
Rhopalonaria attenuata Ulrich and Bassler 
Semicoscinium tenuiceps (Hall) 
Spatiopora maculata (Hall) 
Stictotrypa punctipora (Hall) 
Stigmatella globata n. sp 
Stomatopora dissimilic Vine 
Stomatopora elongata Vine 
Tamiodictya schucherti n. sp 
Thamniscus dichotomus (Hall) 
Trematopora spiculata Hall 
Trematopora tuberculosa Hall 
Trematopora whitfieldi Ulrich 
Vinella ? multiradiata Ulrich and Bassler. . 
Vinella radiciformis (Vine) 
By comparing the species in this list it will be seen that of the 80 forms recorded in the 
Rochester shale 33 occur also in the Osgood beds and but 14 in the Waldron beds. Since 
the Waldron shale has been much more thoroughly searched for bryozoa than the Osgood 
beds, these figures.are significant. It is further to be borne in mind that, since most of the 
Rochester shale species that are known in Indiana as yet only in the Waldron are almost 
world-wide in their distribution, more complete collections from the Osgood beds may be 
confidently expected to materially increase the already large number of species which these 
beds hold in common with the Rochester shale. For this reason the foregoing tabular com- 
parison is not entirely competent Perhaps the surest way of testing the contemporaneity 
of the Rochester and Osgood bryozoan faunas is by means of lists from which species known 
to be of wide range, as well as those common to the Rochester and the Waldron, are excluded. 
Such lists may fairly be said to comprise, so far as known, only the characteristic species of 
the Rochester, though not all of them. 
