BRACmOPODA. 211 



hinge-plate medially divided and without cardinal process. Externally the 

 shells are strongly plicate with broa;d, low fold and sinus, and abrupt anterior 

 slope. 



As far as the structure of the species of Rhynchopora is understood, the 

 complete punctation of the shell must be regarded as the only reliable differ- 

 ential from earlier rhynchonellid groups. The appearance of this character 

 late in the palaeozoic history of the Rhynchonellid^ suggests its similar mani- 

 festation in some of the Spirifers of the Carboniferous, in Syringothyris and 

 in Spiriferina. Future study may show that the inner shell laminae of the 

 early rhynchonellids is not uniformly impunctate, and should this be demon- 

 strated, the appearance in this group of a highly punctated shell like Rhyn- 

 chopora will be more readily intelligible. 



It has been suggested by CEhlert that the term Rhynchoporina may be used 

 in preference to King's term Rhynchopora, on the ground that the latter had 

 been previously used by Latreille for a genus of Coleoptera. The latter 

 author's term appears to be not Rhynchopora, but Rhynchophora, and as the 

 words are etymologically distinct, it seems best not to disturb Dr. King's 

 term. 



