144 Cincinnati Society of Natural History 



the transverse strise are rather indistinct, even under a lens ; on 

 other parts they are sufficiently distinct to somewhat obscure the 

 longitudinal striae. The type specimens were found at the railroad 

 cut 59.7 miles from Ludlow. The species is common also at 59.1, 

 and specimens occur at 59.8, 58.5, 58.3, 56.8, 56.4, 5T6, and 54.2. 



Since the vertical striae, under a lens, are spaced at equal inter- 

 vals, and evidently are as permanent, and usually even more prom- 

 inent features than the transverse striae, it is evident that this spe- 

 cies is distinct from Orthoccras transvcrsuin. Miller, which ranges 

 throughout the Eden, or the transversely striated form occurring 

 in the beds beneath the Eden, at Cincinnati, identified by local geol- 

 ogists as Orthoceras junceuin, Hall. Orthoceras albersi. Miller, 

 listed by Nickles from the beds below the Eden at Cincinnati, is 

 described as having fine longitudinal lines that increase in number 

 with the enlargement of the shell, by implantation, and are dis- 

 posed to a fascicular arrangement that gives the shell the appear- 

 ance of being longitudinally furrowed. If the illustration accom- 

 panying the original description was intended to indicate this fascic- 

 ulation, then our specimen presents nothing similar. Moreover, 

 Orthoceras albersi is described as enlarging to twice the diameter 

 in a length of two inches, giving a larger apical angle, and no 

 mention is made of transverse striae. 



43 — Isotelns. — At my request. Dr. E. O. Ulrich prepared the 

 following descriptions of Isotelns benjainiui and Isotelns coznng- 

 tonensis, two new species from the Cynthiana formation at Cov- 

 ington, and elsewhere in north-central Kentucky. These descrip- 

 tions were accompanied by figures 1 and 4, which are post-lateral 

 outlines of cranidia, and figures 2 and 3, which indicate the out- 

 lines of cranidia anterior to the palpebral lobes. These species 

 are to be credited to Ulrich, and are based upon type material pre- 

 served in the U. S. National Museum, at Washington. 



Isotelns benjajnini, Ulrich. Compared with Isotelns gigas. — 



1 — The genal spines are retained through life, while in /. 

 gigas they are entirely resorbed before the individual attains a 

 length of 3 to 4 inches. 



40 



