BRACHIOPODA. 275 



whose internal structure is but partially known, but which seem to indicate a 

 certain relationship to the centronellids. This author states that all his prepara- 

 tions of the brachidiuin showed the lateral branches to be disconnected, but he 

 believes this to be probably due to imperfect preservation. All of the eight 

 described species of this genus {Terebratula suhvescicularis, Davidson, type) are 

 from the Upper Carboniferous of India, and similar forms have not been iden- 

 tified with certainty in other countries. The Devonian species Notothyris? 

 Smithi, Derby, has a perforated hinge-plate and a brachidium very similar in 

 form to that of Centronella, but instead of the curved anterior plate, it has a 

 simple cross-bar connecting the lateral branches. In Dielasma and other tere- 

 bratuloids we know that the reflected or ascending branches are frequently 

 lost, and it is more than likely that the typical Notothyres possessed an anterior 

 cross-bar as in the Devonian species. 



Genus SCAPHIOCGELIA, Whitfield. 1891. 



1891. Scaphiocctiia, Whitfield. Trans. American Inst. Mining Engineers, vol. xix, p. 106, figs. 1-4. 



"A terebratuloid, brachiopodous shell*, having a strongly convex ventral 

 valve, and a longitudinally and angularly sulcated dorsal valve; both of 

 which are strongly plicated. Internally the ventral valve has a strong, 

 deep, triangular byssal opening and muscular seat, and the dorsal has 

 strong crural processes ; but the loop or calcified appendages are un- 

 known. Shell structure strongly fibrous, without any puncture under a 

 hand-magnifier." 



Type, Scaphioccdia Boliviensis, Whitfield. Devonian. 



Observations. As suggested by Mr. Whitfield, this great shell has, the 

 appearance of a gigantic plicated Centronella, and in the absence of any defi- 

 nite knowledge of its internal structure, may provisionally be regarded as 

 allied to that genus and those plicated centronelloids which have been herein 

 designated by the term Trigeria. The only species known, S. Boliviensis, is 

 stated to sometimes exceed three and one-half inches in length. It was found 

 by Mr. A. F. Wendt in the vicinity of Sucre or Quechista, Bolivia, in a sandy, 



