304 Eepokt of the State Geologist. 



The smallest corallum. of F. conicus in this collection is 

 8 mm. in diameter and the largest 48 mm. The majority of 

 specimens are discoidal, or flattened hemispherical. A few have 

 the characteristic form, being conical or strawberry-shaped. 



Formation and locality. — Indian Ladder, Clarksville, Schoharie, 

 Herkimer Co., and Cumberland, Maryland. 



Favosites Conradi, sp. nov. 

 Plate V. figures 3-5. 



Corallum ramose, branches slender. Corallites polygonal, 

 contiguous, of comparatively small size. Pores large, with usually 

 but a single row to a face. Septa represented by spines which 

 are close set and regularly arranged so as to give twelve longi- 

 tudinal rows, forming at the same time transverse rings. 

 Tabulae complete, straight, and near. The mature corallite are 

 2 mm. in diameter, the cells of various sizes. Usually disposed so 

 that each large cell is surrounded by a ring of smaller corallites 

 of about half its size. Tabulae 1 to 1.5 mm. apart, evenly 

 distributed. 



Although the tabulae are near together, they do not appear so 

 when compared with a closely tabulate form like F. HelderbergicB. 

 The specimens which represent F. Conradi are silicified, and the 

 character of the septal spines is not satisfactorily shown. The 

 cell walls are thin, but, near the surface, they are somewhat 

 thickened by silicification. At this point, the septa are represented 

 by parallel coronae of prominent spines, which are less conspicu- 

 ous a little below, and eventually nearly or quite disappear. The 

 number of septal ridges is regularly twelve. When, . through 

 abnormal growth among the corallites, an epitheca is developed, 

 it is ornamented with fine radiating striae and delicate concentric 

 wrinkles. 



Horizon. — Lower Pentamerus limestone. 



Locality. — Indiaa Ladder, N. Y. 



Favosites spheriGus= Chcetetes {Ptychonema) sphericus, Hall, 

 18Y4. 



Favosites proximus = Choetetes {Ptychonema) proximus^ Hall, 

 1883. 



These two species have been examined with considerable care 

 by means of microscopic sections, and I have been unable to 



