CAMAROPHORIA 169 



Family PENTAMERID^ 

 Genus CAMAROPHORIA King 



Description. Shell usually small or below medium size, rostrate, subo- 

 vate to subpentagonal in outline, with well-developed median sinus in the 

 pedicle valve and fold in the brachial valve, both valves either plicated 

 or with the plications nearly or quite obsolete. In the pedicle valve the 

 dental lamella? are continued anteriorly into a well developed spondylium 

 which is either supported by a median septum or rests directly upon the 

 floor of the valve for a part or the whole of its length. In the rostral 

 portion of the brachial valve the hinge-plate is continuous and is sup- 

 ported by a strong median septum ; between the hinge-plate and the floor 

 of the valve the median septum also supports a concave cruralium which 

 is continued far beyond the hinge-plate, becoming broader and more 

 highly elevated anteriorly ; posteriorly the median septum passes through 

 the cruralium for the support of the hinge-plate, but the extension of the 

 septum above the concave surface of the cruralium soon disappears be- 

 yond the anterior margin of the hinge-plate. 



FIG. 1. A series of eleven cross-sections (X 2 1 /) of the rostral portion of Cam- 

 arophoria schlotheimi (von Buch), the genotype of Camarophoria, from the 

 Permian of Possneck, Germany, showing dental lamellae and spondylium of 

 the pedicle valve, and the median septum, cruralium and hinge-plate of the 

 brachial valve. 



Remarks. Sometimes the genus Camarophoria has been so interpreted 

 as to include a number of rhynchonelloid shells, R. subcuneata and R. siib- 

 trigona, of our Mississippian faunas which are characterized by a median 

 septum in both valves. These shells, however, do not possess the cruralium 

 of the brachial valve and are therefore excluded from the family Pentam- 

 eridce and are included in the present report in the Rhynchonellidce under 

 the genus Tetracamera. In all the species here included in Camaraphoria 

 the characteristic internal. characters of the shell have been determined 

 by grinding the rostral portion of the shells. For comparison similar 

 sections of the genotype, C. schlotheimi (von Buch), have been made and 

 the American Mississippian species agree in all essential generic charac- 

 ters with that species from the Permian of Germany. 



