S. W. Ford—Forms of Brachivpoda. 365 
form, rarely broad+ovate longitudinally, and has an excentric 
apex or nucleus. Around this point the surface lines are 
arranged concentrically. Some of the specimens show also the 
existence of fine radiating lines in the nucleal region. The 
oramen does not appear to be a constant feature. The inte- 
rior of A, granulata has not been observed and the dorsal valve 
1s in doubt. The form is nearly cireular, the deviation from 
and H. impar,* permit us to observe the interior of this piece. 
In neither do we find any trace of muscular scars. In this 
- fe preg rnal for June, 1872. ; 
ae Pingel sg adi oari~ pred poda of Bohemian Basin, 
an a ition; Lut such a compositic 0 eer 
tively stated to characterize any of them (Systéme Silurienne, &e., iii, 1867, p. 66). 
t Bull. Soe. Geol. Fr., t. xvii, p. 532, pl. vim, fig. 2. 
