NAPLES FAUNA IN WESTERN NEW YORK, PART 2 295 



the species pass into Paracardium, a group from which Buchiola is distin- 

 guished less in kind than in degree. The structural features of Buchiola 

 appear to us, from the study of delicate replacements, to be these. The 

 cardinal line is long and straight, and the beaks we regard as prosogyre ; 

 a narrow sometimes curved or concave, almost linear cardinal or ligament 

 area is developed, on the outer edge of which we find in many cases a 

 row of minute and often irregular denticles. This is a modification which 

 is so frequently absent that we have repeatedly suspected it to be due to 

 incomplete replacement, but in our present judgment such is not the nature 

 of it. This row of denticles may extend for nearly the whole length of the 

 cardinal line or for only a part thereof, and it is probable that those from 

 opposite valves interlock. It is quite certain that these denticles are not 

 termini of radial subumbonal plications, as somewhat similar appearances in 

 Praecardium are believed to be by Neumayr and Beushausen. 



Beushausen has done an estimable service in indicating the specific 

 distinctions existing in the Devonic material of Germany which has long 

 and everywhere passed under the name Cardiola retrostriata v. 

 Buch. Similarly in New York all expressions of this genus have commonly 

 passed asAvicula or Glyptocardia speciosa Hall. Though we 

 find less diversity of specific forms in the Appalachian than in the German 

 Devonic (18 species), yet we find it necessary to enter on some restriction 

 of the old specific name, in order properly to apprehend the value of the 

 genus. 



Buchiola retrostriata v. Buch. (sp.) 



Plate 10, fig. 1-14 



Venericardium retrostriatum v. Buch, Ueber Goniatiten. 1832. p. 50 

 Avicula speciosa Hall, Geology of New York; rep't on fourth dist. 1843. 



p. 243, pt 106, fig. 1, ia 

 Cardiola speciosa Hall, Paleontology of New York. 1883. v. 5, pt 1, plates 



and explanations, pi. 70, fig. 6-8 (not fig. 2-5, 9) 

 Glyptocardia speciosa Hall, Paleontology of New York. 1885. v. 5, pt 1 



Lamell. 2, p. 426, pi. 70, fig. 6-8 (not fig. 2-5, 9) 

 Cardiola retrostriata Clarke, U. S. Geol. Sur. Bui. 16. 1885. p. 58 



