1(12 



Ni:\N YORK STATE MUSEUM 



])(M'ii ((Hiijinrcd with tlic iiiiprcssioii of a colTs fool. 1\ 1i i p i d o - 

 111 (' 1 1 a 111 u s {• 11 1 o s a I li,ii". TO] is a sinall(*i- tvpo, Mith less 

 marked iimsculai- inijircssioiis. L c p i o s i r o |» li i a in a «i" - 

 11 i f i (• a [Wix. 77 |, a lariLic iicarlv Hat species, wiili i>i'oiioiiiiced 

 (li\('i iiciii imisiiilai- iinprcssioiis and tine i-a<1iai inu striae, is like- 

 wise coiiinioii, to;:,('t lier with s(=\-eral other sjiecies of the ji'eniis. 

 S |i i r i f e r in n r e li i s o n i [fii!,-. 78 J and S . a r e n o s ii s [fig. 

 71) I are the iiiosi characteristic brachiojxxls of this formation, the 



former (list in<>iiish( d hv its broad 

 i'onnd(Ml plications, and smooth 

 fold and sinns, the other by its nu- 

 merons low ronnded i)li cat ions 

 which also extend across the fold 

 and sinns. Internal molds of 

 the^e two species are character- 



Fi^-. 80 E a t o n i a p e c u 1 i a r i s 



ized by strong elevations in the 



rostral cavities, which are dif- 

 ferently marked in the two species, as shown by the illns- 

 trations. E a t o n i a p e c u 1 i a r i s [fig. 80] . a small species 

 with a strong anterior deflection, and the snrface marked 

 only by fine radiating striae is common. Several large 

 i-lnnchonelloids occnr of which IM e t h o r h y n c h a bar- 

 r a n d e i [fig. 81] is the most striking. Others are IM e t h o - 

 r h y n c h a p 1 e i o j) 1 e n r a [fig. 82], (' a m a r o t o e c h i a 

 oblata [fig. 8:i] and C. fitchana [tig. 84J. L e ]) t o - 

 c o e 1 i a f 1 a b e 1 1 i t e s [fig. 85] is not nncommon and is the 

 only small jdicated shell with flat brachial and moderately convex 

 ])edicle \alve. One of the most characteristic species of this 

 horizon is the large, elongate, robnst Rensselaeria 

 (► V o i d e s [fig. 8t;] readily known by its convexity and regnlar 

 snrface sli-ialion. With it occnrs the smaller, gently convex 

 M <' ga I a n t e r i s o v a 1 i s [fig. 87]. in which tlu^ snrface striae 

 sehloiii api;eai-. 



The pi'lecyjiods are chielly i('|»resented by the large IM e r i nea 

 t e X I i I i s \ai'. a re n a i' i a | tig. 88], with its sharj) stri^alions; 

 and 1* I . gebh a rd i [ lig. 8!)], with Hat, ronnded plications. 



