PLATE XXXVI. 



PAGE. 



Fig. 1. Orthoceras (Actinoceras) Youngi, Foerste 537 



1 . From the Orthoceras block, a large block full of fossils from a loc*al deposit near the 



base of the Clinton at Huffman's quarry, south of Dayton. The block was acci- 

 dentally saved by a quarryman who became interested in three large fragments of 

 this species included in the block. Had some collector been at hand to explore the 

 deposit it would have probably proved the richest locality so far discovered in the 

 State for the rarer fossils. H. O. 



Fig. 2. Cyrtoceras CwnTonense, Foerste , 534 



2. a , A rapidly curving fragment ; b. a section of the siphuncle of the same : c, a 



transverse section. H. O. 2^, a less rapidly curving fragment believed to resemble 

 a more matured stage of growth of the shell ; d, a section of the siphuncle of the 

 same. B. O. Ohio State Univ. collection. 



Fig. 3. Ptii,odicTya i^anceoIv ata, Goldfuss, var. Americana, Foerste 598 



3. a One of Jhe more lanceolate fronds with the median band and some of the stronger 



wrinkles of growth intentionally emphasized; b , a broader frond from the same 

 locality, showing the more aberrent form of the species, upon which the variety 

 was founded. S. H. O. 



Ptilodictya WhiTFIeldi, Foerste 598 



Orthoceras (Actinoceras) Clavatum, Hall 538 



a, A fragment showing the tapering of the species ; *, a section of the upper end ; c a 

 section of the lower end; siphuncle. B. O. Ohio State Univ. collection. 



Orthoceras (Eu-Orthoceras) ignotum, Foerste 538 



a, b, c, Three separate fragments showing the characters of this species. H. O. 

 Gomphoceras Ortoni, Foerste 533 



7. a, b, same as figs. 8 a, b, of plats 32, after more careful, cleaning of the original speci- 

 , men. The cleaning tools may have emphasized characters in the soft limestone, 



but every attempt was made to avoid that result. B. O. c. A specimen of Gom- 

 phoceras from the same quarry. B. O. Ohio State Univ. collection. 



Fig. 8. Orthoceras (Discosorus) conoideum, Hall 546 



8. T. F. O. Collection of Dr. Chas. Welch. 



Fig. !>. Iu^eNos, Glabella 525 



tl. T. F. O. Collection of Dr. Chas Welch, 



