258 



Fig. 175. PalaeoneOo fecunda. Right and left valves of different individuals of the 

 usual form ifrom Hall). 



Found in tht lower Moscow shale, at Sections 4 and •"> 

 (rare); and in the Lower shale, down to twenty-one feet 

 below the Encrinal limestone, at Sections 5 to 7. 



Pal.eo\i;ii.o\muta. Hall. (Fig. 176.) ( Pal. X. Y., Vol. 



V. } Pt. L, p. 337, PL LXIX.) 



Distinguishing Characters.— Like the preceding in outline 

 and proportions, but entire surface marked by strong, regu- 



Fig. 176. Palceoneilo muta. Two left valves and one right valve of different sizes 

 (from Hall i. 



lar, lamellose, elevated stria?, with very fine intermediate 

 stri;e. 



Found in the lowest two feet of the Moscow shale, at Sec- 

 tions 4 and 5 : and in the shales down to and in the Stropha- 

 losia bed (very rare and at great intervals). 



Palceoneilo emarginata. (Conrad.) (Fig. 177.) (Pal. 

 X. Y.. Vol. Y.. Pt. L, p. 338, PI. L.) 



< ■ ' 



"^ 



1 n.. 177. Palceoneilo e>i>( i rt/ in ata. Two right and two left valves, showing variations 

 (from Hall). 



