BRACHIOPODA. 



89 



Sections of Pentamerellas. 



1-5. Pentamerella arata (Conrad). Sections of a small specimen from the Mineola . 

 The brachial valve was 11}^ mm. long and the sections were made 1 mm., 

 3 J/2 mm., 4.5 mm., 4 6 mm. and 5.2 mm. from the beak. The septae continue 

 for less than one millimeter in front of the last section. 

 6. Pentamerella arata (Conrad). Section near the beak of a specimen from the 

 Jeffersonville beds of Indiana. 

 7-12. Pentamerella fultonensis Branson. Sections of a specimen with a brachial 

 valve 14 mm. long. The sections were made 1.5 mm., 2.1 mm., 3.2 mm., 5 mm., 

 5.7 mm. and 6.3 mm. from the beak. 

 All sections are arranged in series with the smaller numbers nearer the beak. 



Genus Gypidula Hall 



Gypidula manonensis Greger 

 Plate 16, figures 17-20. 

 1920. Gypidula marionensis Greger, Am. Jour. Sci., vol. 50, p. 24. 



Description — Shell small subglobose, the pedicle valve much more convex than 

 the brachial. In old specimens the convexity of the pedicle valve is proportionately 

 much greater than in young specimens. The beak of the pedicle valve is strongly in- 

 curved but ordinarily not overlapping the beak of the brachial valve. A very short 

 median septum. The shell is smooth and has no indication of fold or sinus. The brachial 

 valve is much less convex than the pedicle. It is smooth and has no fold or sinus. The 

 crural plates and septae extend about half the length of the valve and are nearly parallel, 

 though the septae converge to form a point at their anterior end. 



The dimensions of an average specimen are: Length 10 mm., width 9 mm., thick- 

 ness 9.5 mm. A specimen with an unusually large pedicle valve measures: Length 

 9 mm., width 10 mm., thickness 12 mm.; in this specimen the height of the pedicle valve 

 is 9 mm. 



The distinguishing feature of this species are its smoothness, small size, and unusual 

 height of the pedicle valve. 



Greger published no description or figure. 



Occurrence — Abundant in the Cooper of Monroe County. 



