OF DENISOX UNIVERSITY. 69 



This species is found rarely in ihe shales below the congl. I. 



There is an a priori improbability that this species exists in Bel- 

 gium as well as in America, but the identification of Dekoninck is 

 positive. 



San6innolites iSphcnotiis) contraehts, '^^'- '^^• 

 (Plate XII, Fig. 4.) 



A form identified with this Cliemung species is found in shales at 

 Moot's run. in the nodule layer, ht-nce perhaps sixty feet below the 

 horizon of S. rigidus=transversus. From that species it differs in be- 

 ing less robust, longer, less rigid, and in having less obtuse post infe- 

 rior extremity. 



T\\Q group of sjjecies here associated is a very intimate one and 

 the specific distinctions may prove illusory. 



Saii^idnolites Sphenotiis) flavins, 'I ? 

 (Plate IX, Fig. lo. ) 



I'he resemblance between Sp. valvulus and Sp. flavins, as fig- 

 ured by Hall, is so close that one would be tempted to combine them 

 unless full suites attest their autonomy. 



Our specimens vary considerably, and in the surface characters 

 resemble Sp. flavins, but often have more the ou'line of Sp. valvulus. 

 The resemblance to small forms of Sanguinolites Jiaiadifonnis is great. 

 From S. unioniformis with which they are associated they may be dis- 

 tinguished by the greater size and more produced posterior margin. 

 Length 48 mm; width 18 mm. 



Specimens found only in layer of shale a few feet below con- 

 glomerate I. 



Sanguinolites (Glossifes) (innj^ildliniis, Win? 



This species is apparently represented in our collections, but not 

 in specimens in suitable condition to describe. Its |)Osiiion is in the 

 shale below congl. I. 



