40 The Ohio Naturalist. [Vol. XIII, No. 2, 



The two most characteristic fossils of the lower part of the 

 Cloche island beds are Columnaria halli and Stromatocerium 

 rugosum. Columnaria halli ranges from the base of these beds to 

 about 45 feet above the base. Stromatocerium rugosum was found 

 about 20 feet above the base and may occur also at other levels in 

 the lower part of these beds. It is evident that both Columnaria 

 halli and Stromatocerium rugosum may be looked for in the under- 

 lying Swift Current limestones, since Columnaria halli occurs in 

 the upper or Leray member of the Tyrone formation in Central 

 Kentucky, and has been found also in the Lowville at Watertown, 

 New York; while Stromatocerium rugosum is found in the Lowville 

 northeast of Watertown, New York. 



Reccptaculites occidcntalis begins its range about 20 feet above 

 the base of the Cloche island beds; it becomes common at ?)':) feet 

 above the base, where the first specimens of Maclurea logani are 

 seen. No specimens of Gonioccras anceps were discovered within 

 80 feet of the base of these limestones, but they begin their range 

 a short distance above this level, and all three species, Reccptacu- 

 lites occidcntalis, Maclurea logani, and Gonioceras anceps extend to 

 the extreme top of the section as exposed on Cloche island, but 

 have not been found in the lowest Trenton layers found on Goat 

 island, immediately southward. The presence of these fossils is 

 therefore used here to discriminate the Black river from the over- 

 lying Trenton limestones. It should be remembered, however, 

 that Reccptaculites occidcntalis has been identified by Ulrich from 

 the Curdsville bed, in the lower Trenton of Kentucky, and species 

 of Maclurina, which can not readily be distinguished from Maclu- 

 rea in the field, occur in the Trenton of the northwestern states. 

 Moreover, considering the very close similarity of the Curdsville 

 fauna on Goat island to that found in the underlying Cloche 

 island limestones, it would be rash to state that no Gonioceras 

 ever will be found in the Curdsville. The chief point is that the 

 great abundance of Reccptaculites, Gonioceras, and Maclurea dis- 

 tinguishes the top of the Cloche island Black river limestones 

 readily from the base of the lowest Trenton limestones found on 

 Goat island. 



Near the tojj of the Black river exposures on Cloche island, 

 within a mile of the southwestern termination of that part of the 

 railroad which crosses Cloche island, Protarca vctusta, Calapoccia 

 canadensis, Petraia aperta, a large celled form of Columnaria 

 alveolata, with more or less discrete and rounded corallites, 7 mm. 

 in diameter, and a specimen doubtfully identified as Eurystomites 

 undatus occur. Of these, Protarca vctusta has been recorded 

 hitherto only from the lower Trenton, but the other four forms 

 mentioned have so far not been recorded from the Trenton, and 

 are regarded as characteristic Black river species or varieties. 



