218 



Geologisl and Palaeontologist for 1896. Faunas of the 



Hamilton Group, etc., p. 276. 1 

 Distinguishing < 'haracters. —Small size: transverse out line, 



the pedicle valve being much broader than long; convex 



brachial valve, usually bear- 

 ing a shallow depression 

 along the center; numerous 

 elongated pits covering the 

 surface, showing spine bases 



Fk; 126 Ambocaelia nana. Cardinal and . •,, j • , 



dorsal views of ;i characteristic specimen. m well-preserved specimens. 

 from the Nautilus bed, enlarged (after Gra- i-.ixTi.-i 1 i 



bau). Found m the Nautilus lied 



a1 the base of the Hamilton shales, on the Lake Shore and in 

 Avrrv's Creek (abundant); Strophalosia bed, on the Lake 

 Shore (very rare). 



Amhohelia i'i;,i:rMBO.\A. Hall. (Fig. 127.) (Pal. X. Y., 

 .Vol. IV., p. 262, PI. XL1V.) 



Distinguishing Characters— Large size; sub-globose char- 

 acter: short hinge line: length greater than width: ventri- 





Fig. 127. Amboccelia prceumbona. Two brachial valves; pedicle valve and profile of 

 same (from Hall). 



cose pedicle valve, with narrow depression along center; 

 moderately convex brachial valve, occasionally bearing a 

 median depressed line. 



Found in the upper Moscow shale down to four feet from 

 1h«' top, at Sections 1 to 5 (abundant). 



A.MBOCCELIA bpinosa. Clarke. (Fig. 128.) (13th Ann. 

 Rep'1 State Geol. X. Y.. Vol. I., p. 177. PL IV.) 



Distinguishing Characters.— Rather large size; hinge line 

 equal to width of shell: brachial valve concave anteriorly, 

 with upturned margins; low median elevation, indistinct 

 and disappearing towards the front: elongate surface pits, 

 probably marking positions of spinules. 



