LMM 



Fig. Hi*. < "honetes coronatus Profile of the pedicle valve, shown in full view below it : 

 ventral and profile virus of another specimen: two interiors of brachial valves, showing 

 differences in cardinal process, strength of muscular impressions, etc. (from Hall). 



and 6: 

 Creek. 



Pleurodictyum beds and shale above, in Avery's 



Genus PK()DTXTP:LLA. Hall. 



[Ety. : Diminutive of Product us.] 



(1867: Pal. N. Y., Vol. IV., p. 153. 1892: Pal. N. Y., 

 Vol. VIII., Pt. I., p. 328.) 



Shells small: concavo-convex, the pedicle valve strongly 

 convex, and produced anteriorly. The beak of the pedicle 

 valve is overarching, and the hinge line straight, with a nar- 

 row cardinal area, a deltidhim and small teeth. Brachial 

 valve small, concave operculiform, with a straight hinge 

 line, dental sockets, and crural plates. Surface marked by 

 radiating ridges, which bear spines at intervals. 



Productella navicella. Hall. (Fig. 111.) (Pal.N.Y., 

 Vol. [V.,p. 150, PI. XXIII.) 



Distinguishing ( 'haracters.- 



Small size; great length, 

 which exceeds the 

 width ; hinge line less 

 than width of shell : 

 pedicle valve verygib- 



Fio.lll. Productella navicella. Dorsal, ventral and b()US, With the beak 

 profile views ..t an elongated specimen of the variety t • i 

 rurrlng in the Encrinal limestone (fr Hall). vei'V lUUCll incurved. 



1 



