74 A^'g- P- Focrstc 



Orthoccras fostcri bed, at the base of the Middle or Clarksville 

 division of the W'aynesville bed. The specimen had been crushed 

 laterally toward the apical end. The distance between the septal 

 impressions is 7 or 8 mm. At and beyond a distance of 75 mm. 

 from the apical end, these impressions are distinct. Nearer the 

 apical end, these impressions are represented chiefly by equally 

 distant transverse, obliciue wrinkles. 



A much smaller, but otherwise similar specimen was found 

 in the Richmond group at Madison, Indiana, presumably in the 

 Waynesville member. 



The similarity to Snccoceras appears confined to the exterior 

 appearance of the nepionic bulb. No structure can be detected 

 within this bulb. The upper end of the specimen from Clarksville 

 is covered on one side by a thin encrusting- expansion of some 

 bryozoan, indicating that the remainder of the shell had been re- 

 moved before the siphuncle had become imbedded in the mud at 

 the bottom of the sea. The w-alls of the siphuncle are very thin, 

 and those of the remainder of the shell must have been very fragile 

 or easily dissolved. These siphuncles probably belong to a new 

 genus, as yet too imperfectly known to admit of characterization. 



Cyrtocerina madisonensis, Miller. 



Cyrtocerina madisonensis is found in considerable numbers in 

 the Hitz layer, at Madison, Indiana, but has not been noticed else- 

 where so far. 



Orthoceras (Dawsonoceras) hammelli, sp. nov. 



(Plate I, fig. 4-) 



At the top of the Saluda bed at the Dog Falls, on Saluda creek, 

 in Jefferson county, Indiana, an annulated species of Orthoceras 

 occurs in which the annulations, from one point of view, are mod- 

 erately inclined. One fragment, 53 mm. in length, wnth 15 an- 

 nulations, has a width of 19.5 mm. at the top and 17.3 mm. at the 

 base. The annulations are broad and low, and their elevation 

 above the intermediate grooves is scarcely half a millimeter. About 

 5, sometimes 4 or 6, distinct longitudinal striae occupy a width of 

 5 mm. near the top. Between each pair is a less distinct striation, 

 and usually two additional striations readily visible only under a 

 lens. In addition to the annulations there are transverse striations, 

 visible only under a lens. About four septa occupy a length equal 

 to the width of the shell. 



