Makylaxd Geological Survey 611 



Family PRAECARDllDAE 



Genus BUCHIOLA Barrande 



This iiaiiu' was introduced for shells which had been passing current 

 in European literature as YenerirardiuTn reirostriaium von Buch and 

 Cardkim palmatiim Goldfuss. Professor James Hall had at an early date 

 described a species of the same general type as these under the name 

 Avicula spcciosa and afterwards (in 1885) introduced the generic name 

 GJyptocardia for this particular species, a term which was too late for 

 recognition, as Barrande's name already occupied the field. These small 

 shells all agi-ee in the general expression of their exterior which is, in a 

 characteristic example of the genus, quite strongly ribbed, the ribs bear- 

 ing sharp recurved and often chevron-shaped concentric ridges. Uniform- 

 ity in the character of the exterior has led to the assembling, up to within 

 recent years, of all forms known under one or another of the specific 

 terms above mentioned, but a more careful analysis of the species under- 

 taken by Beushausen has shown the existence, in the stages of the German 

 Devonian, of a ver\' considerable number of well-defined specific types. 

 Similarly a careful restudy of the shells which have been known in Xew 

 York as Avicula or Cardiola, or finally Glyptocardia spcciosa Hall, which 

 had been assigned a range from the Marcellus shales to and into the 

 Portage stage, shows that here again a number of distinct, specific types 

 have been brought under one tenn. The senior autlior has had occasion to 

 work out in some detail the nature, persistence and local value of the 

 various types of Buchiola in the Kaples fauna of western New York and 

 the facts there acquired are supplemented in a very interesting manner by 

 the manifestations of this genus in the same fauna in its Maryland repre- 

 sentation. 



The shells of Buchiola were small, diaphanous, fragile bodies apper- 

 taining to the group which Xeumayr termed the Palgeoconchte and which 

 Beushausen proposed to change on account of their not being essentially 

 early types, to the form Cardioconcha\ In these shells the hinge is long 

 and straight, and bears a narrow linear ligamental area. Preparations of 

 delicate replacements of the shell in bariTim sulfate, acquired from the 



