60 AMERICAN JOURNAL 



We may now turn our attention to the additions and correc- 

 tions which it is desirable should be made to my previous paper. 



The page numbers refer to those of the original paper, Am. 

 Journ. Conch, vi, Part 2, pp. 88—168, 1870. 



Pages 98, 107, 138. By an unfortunate wording the diagnoses 

 of Walclheimia and Kraussina are made to read as if the mouth 

 was situated outside of and behind the brachial disk, whereas 

 the meaning intended to be conveyed was that the brachial cirri 

 were not continued behind the mouth. This observation having 

 been made on dry specimens, which did not convey the characters 

 fully, should be eliminated ; as elsewhere stated, the mouth in 

 the Brachiopods is invariably situated within the brachial disk 

 behind the great mass of the brachia, but before their posterior 

 junction. In some species the cirri appear not to be continued 

 behind the mouth, while in others they reach their greatest 

 development in this position. 



Page 98. Eiehwaldia sultrigonalis, Bill., is from the Trenton 

 limestone. Some information in "regard to the interior of what 

 Prof. Hall regards as an allied species, is to be found on pp. 

 274-8 of the XXth report of the Regents of the University of 

 New York, Albany, July, 1868. 



The type of Leptocoelia, Hall, is the L. concava, This was 

 afterwards erected by Prof. Hall into a new genus, Coelospira, 

 leaving those species of which the interiors were still unknown, 

 under the first name. This, however, is clearly inadmissable ; 

 the first name must be retained and Coelo spir a f-d\\s as a synonym 

 of it. 



Pages 100, 154, 163-4-5. Spondylobolus has been misprinted 

 Spondylobus throughout, and this was not noticed in the proofs. 

 A similar misprint occurs in Davidson's Introduction to the 

 Classification of the Brachiopoda. 



The following is the synonymy of the order which includes 

 the articulated Brachiopoda : 



Order ARTHROPOMATA, Owen. 



Arthropomata, Owen. Enc. Brit. Ed. viii, xv, article Mollusca, 

 p. 336, 1858. 



= Apygia, Bronn, Klass. Ordn. Thierr. iii, 1st Abth. p. 301, 

 1862. 



= Artieidata, Huxley, Lect. Class. 1864. Intr. Class. An. p. 

 116, 1869. 



Intestine ending in a closed sac. Lobes of the mantle united 

 behind. Valves articulated by teeth and sockets. 



