206 



Trans. Acad. Sci. of St. Louis. 



UPPER YELLOW SANDSTONE AT 

 BURLINGTON. 



Dentalium grandaevum 



NORTHVIEW SANDSTONE. 



Orthoceras indianense 

 Triboloceras digonum 

 Proetus sp. undet. 

 Spirophyton sp. 



A comparison of these two lists shows a large number of 

 species in each which do not occur in the other, but at the 

 same time certain strong bonds of relationship are exhibited. 

 This relationship is best shown by the pelecypod genera Per- 

 nopeclen, Palaeoneilo and Promacrus. The genus Pernopecten 

 is one of the commonest forms in the Northview fauna, it is 

 also abundant in the upper yellow sandstone at Burlington, 

 but has an even greater representation in the superjacent oolitic 

 limestone. In all these beds the genus is represented by a 

 common species, P. cooperensis, which is also exceedingly 

 common in some of the beds of the Chouteau limestone of 

 central Missouri. Palaeoneilo is represented by two species 

 in each of the above faunal lists, which in both cases may be 

 considered as representative species, those in the two faunas 

 being closely allied. The genus is largely represented in the 

 higher Devonian faunas but is entirely absent from the Chono- 

 pectus fauna where so many Devonian genera of pelecypods 

 are present. Promacrus is one of the most conspicuous 

 genera in the Northview fauna, but only a single specimen 

 has been observed from Burlington, which is, however, a 

 member of one of the two Northview species. This genus is 

 also not uncommon in some beds of the Chouteau limestone 

 of central Missouri. 



The species in the upper yellow sandstone fauna at Burling- 

 ton which are known to occur in other faunas are only thir- 

 teen in number, but of this number two only, StraparoUus y 

 angularis and Dentalium grandaevum occur in the Chono- 

 pectus sandstone of the same section. Cyrtina acu^ostris 

 which is but doubtfully identified in the Burlington section, 

 is certainly known elsewhere only in the Louisiana fauna. 

 Orthothetes inaequalis and Spirifer centronatus are known 

 from the Waverly sandstone of Ohio. The remainder of the 

 thirteen species, Leplaena rhomboidalis, Productus arcuatus, 



