BRACHIOPODA. 129 



differs from that of Parazyga hirsuta in having the lateral portions united by a 

 central lobe, and the entire process supported by a short, septiform median 

 buttress. These differences in the hinge-plate are of inconsiderable import- 

 ance and the loop is essentially like that of P. hir- 

 suta ; its posterior geniculation being more nearly 

 at the middle of its length, the anterior bend 

 shorter, the entire upper portion of the loop above 

 the geniculation of the lateral branches being *'"'•'"• ''°"'' ""''"■''"''''• ^^^^•,"'"'- 

 expanded laterally and the lamellae much broadened. 



Genus ANOPLOTHECA, Sandberger. 1855. 



PhATE LII. 



1853. Terebratitla, Schnur. Besthr. dei- Eifel. Bracliiopoden, p. 180, pi. xxiv, fig. 3. 



1855. Anoplotheca, F. Sandbebgbr. Sitzungsber. der k. k. Akad. der Wissensch. math, naturw, Clas?. 



pt. xvi, p. 5; pt. xviii, p. 102, ^\. i, tigs- 1-6. 



1856. Productiu, Anoplotheca, Thk SANDBSRaEBH. Verstein. des rbein. Schicht. syst. Nassau, p. 351, 



pi. xxxiv, tig. 18. 

 1856. Anoplotheca, Sdbss. Clagsification der Brachiopoden von Th. Davidson, p. 94, pi. iii, fig. 26. 



This name was introduced by Dr. Fridolin Sandberger, who described, first 

 in April, 1855, the general external and internal characters of the genus, and 

 in November of the same year, gave a partial account of the brachial apparatus. 

 The following description is a translation of that given by Suess in his German 

 edition of Davidson's " Classification of the Brachiopoda," and is derived from 

 the two accounts published by Sandberger. 



" Shell oval in outline, concavo-convex, without pedicle-opening, cardinal 

 area or deltidium. The hinge-line is arched, the inner margins somewhat ele- 

 vated and radially grooved by the impressions of the cilia of the mantle. The 

 convex ventral valve is the larger. On its interior, near the hinge, lie two 

 stout teeth ; along the median line from the beak, for one-half the length of the 

 valve, extends a narrow ridge, which is divided at its lower extremity ; on 

 either side of this may be seen the impressions of the cardinal muscle, and at 

 its lower end the little ovate scar of the adductor. Near the upper end of the 

 cardinal scar originates, on each side, the main trunk of the vascular sinuses, 

 which pas.se8 rather obliquely toward the margins, but before reaching them 

 sends off a trifurcate lateral branch toward the center, and is itself divided. 



