(1 II A PT VAi V. 



CJ^ASSIIICATIO^V OF Illi: BUACiriOP()J>A. 



HISTORICAL. 



Fabiiis Coluiniiii, in lOK), and Martin Lister, iu 167S. were the iirst 

 to describe bracliiopods, calliiii;' them (JoncJue anomiiv. (Irundler, ia 

 1774, was, however, the first to give a good ilhistration of a brachiopod 

 in Terehratidinacapnt-serpentis. Iu 1818 Lamarck recognized 5 genera, 

 including the operculate coral Calceola. Otiier genera were added by 

 Sowerby, Dalman, and Defrance, from 18LM) to 1830, and in the early 

 forties about 1,500 species had been defined. In 1810 King recognized 

 40 genera in IG families, and Bronu, iu 1862, knew nearly 2,000 species 

 and 51 genera. At present there are probably no fewer than 0,000 

 species known in 321 genera, grouped in 31 families, 9 superfamiles, 4 

 orders, and 2 superorders. 



Since 1858 the class Brachiopoda has been divided by nearly all sys- 

 tematists into two orders, based on the presence or absence of articu- 

 lating processes. These two divisions were recognized by Deshayes as 

 early as 1835, but not until twenty-three years later were the names 

 Lyopomata and Arthropomata given to them by Owen. These terms 

 have been generally adopted by authors, though some prefer Inarticu- 

 lata and Articulata of Huxley, or Bronn's Ecardines and Testicardines. 

 Bronn, in 1862, and King, in 1873, while retaining these divisions, con- 

 sidered the presence or absence of an anal opening more important 

 than articulation, and accordingly proposed the terms Pleuropygia and 

 Apygia, and Trententerata and Clistenterata, resj)ectively. In many 

 Paleozoic genera of Clistenterata it has been shown that an anal open- 

 ing was also present, and therefore the absence or presence of this 

 organ is not of superordinal value. Beecher writes:^ 



The (lorsfil beaks of Amphij^enia,, Athyris, Cleiothyris, Atrypa, and Rbyiicbouclla 

 arc usually notched or perforate. The perforation comes Irouithe union of the crural 

 plates above the floor of the beak leaving a passage through to the apex. A similar 

 opening occurs between the cardinal processes iu Strophomena, Stropheodonta, and 

 allied genera, an<l the chilidiummay also be farrowed, as in LcpUvna rhomho'uhtUs. This 

 character is evidently in no way connected with the pedicle opening, but points to 

 the existence, in the early articulate genera, of an anal opening dorsal to the axial 

 line, as in the recent Crania. This dorsal foramen was described and figured by King 



'Am. Jour. Sci., 3d series, Vol. XLIV, 1892, p. 147. See also Kin<;, A Monograph of ttie Permian 

 Fossils of Kns.'lan<l, 1850; and OChlert, yisclier's Manuel de Coucliyliologie, Appendice, 1887. 



Bull. 87 8 113 



