124 Cincinnati Society of Natural History 



on Cloche Island, in Ontario, Canada. In these Black river forms 

 the corallites are very large, often reaching a diameter of 7 mm., 

 and have a tendency to be discrete, with rounded corallites. For 

 these the term Columnaria alveolata-discreta will prove convenient. 



2 — Diplograptus cf. putillus — A species belonging to the 

 group of Diplograptus (Mesograptus) putillus, Hall, occurs at the 

 railroad cuts 58.5, 58.3, 57.6, 57.4, and 56.4: miles from Ludlow. 

 Dr. Ruedemann cites this fossil from the lower third of the Eden 

 at Cincinnati Ohio, and Nickles gives its range as through the 

 Eden. Dr. Ruedemann calls my attention to the fact that the 

 Rogers Gap specimens approach nearest in size to the mutation 

 eximius, occurring in the Canajoharie and Snake Hill beds of the 

 Trenton section in New York, and suggests the probability of 

 several species being hidden under the name putillus. Diplo- 

 graptus putillus and the mutation eximius are illustrated in Part 2 

 of Ruedemann's memoir on the Graptolites of New York, pub- 

 lished by the New York State Museum in 1908. 



3 — Ectcnocrinus grandis, Meek (Plate I, Figs. 8A, B, C, D) 

 — A species intermediate in size between Ectenocrinus simplex and 

 E. grandis occurs at the railroad cut south of Rogers Gap, and 

 also northward, at 59.4, 59.1, 58.5 and 54.5 miles from Ludlow. 

 While probably not of the same species, I can find no means of 

 distinguishing the Rogers Gap species from E. grandis, except its 

 slightly smaller size. Both E. simplex and E. grandis are charac- 

 teristic Eden forms, in the vicinity of Cincinnati. Perhaps, on 

 that account, the comparison should have been made with Ecten- 

 ocrinus canadensis, Billings, from the Trenton of Ottawa and Mon- 

 treal, which is closely similar to E. grandis. Owing to the pres- 

 ence of syzygies in the arms of this genus, all of the species have 

 more or less irregularities in the number of post-radial plates — 

 two often being replaced by one of about the same size as the two 

 combined. Such syzygies are common in the Rogers Gap speci- 

 mens, not only in the brachial but also in the radial series. The 

 column diminishes rapidly in size, from 3.5 mm. at the base of 

 the calyx to 1.8 mm. within a distance of 4mm. At a distance 

 of 25 mm. it still has a diameter of 1.8 mm. At the base of ths 



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