The New SrEciES of Brachiopoda, 329 



ous with the broad margins. Umbonal cavities very short, rarely 

 reaching to the hinge-line and sometimes scarcely more developed 

 than in Dinobolus. Cardinal slope well defined and divided by 

 a deep longitudinal groove. Cardinal buttress faint. Platform 

 scarcely developed ; the scars upon its surface usually faint, but 

 the lateral impressions sometimes sharply defined. Crescent and 

 terminal scars generally distinct. Pallial sinuses usuially discern- 

 ible. Brachial valve with a low, rotund beak and transversely 

 striated area. Umbonal cavity deep. The deep groove of the 

 crescent is followed within by a sharply elevated ridge extending 

 for the entire length of the cardinal line ; terminal scars gener- 

 ally deeply impressed and apparently compound. Platform rep- 

 resented only by a median thickening of the muscular impressions, 

 having the characteristic Y-shaped outline and sometimes divisi- 

 ble into the component scars. From the anterior extremity of 

 this muscular area two diverging ridges pass toward the anterior 

 margin ; these may be connected with the pallial sinuses. 



This shell is readily distinguished from all other described 

 species by the general tendency toward suppression of the plat- 

 forms and muscular scars, the broad surface of contact, and the 

 diverging anterior furrows of the brachial valve. 



From the dolomites of the Niagara group, between Cedarliorgh 

 and Grafton^ Wisconsin, 



Monomerella Kingi. 



Plate 2, figs 1, 2. 



Monomerella Kingi, Hall. Palaeontology of N. Y.. vol. VIII, pt. 1, p. 174, pi. 

 ivd. figs. 1,2. 1892. 



Shell subcircular or longitudinally oval. Pedicle-valve prob- 

 ably with a low cardinal area, as far as may be judged by the 

 size of the casts of the umbonal cavities, which are quite short 

 mamiform, not extending to the cardinal line. Cardinal buttress 

 strong, produced as a septum nearly to the anterior edge of the 

 platform. Platform well developed, broadly Y-shaped ; anterior 

 wall vertical, not excavated ; surface marked by strong impres- 

 sions of muscular attachments. Crescent distinct, terminal scars 

 very prominent. Brachial valve with the umbonal region much 

 thickened ; the platform sharply Y-shaped, its anterior wall being 

 considerably excavated to form imperfect vaults ; the whole ele- 

 42 



