502 



FOSSIL BRACHIOPODA 



xars, which are rarely ilivisihle into anterior and posterior 



pairs. 



In Lei^taena (Fig. 334) the occhisor scars {a) in the ventral 



Fio. 331. — ALrypa reticn- 

 laris. (Wenlock Lime- 

 stone. ) 



Fin. 332. — Interior of the same, seen 

 from the dorsal side, showing 

 brachial spires. (After Hall.) 



valve are narrow and median, and are enclosed l;)y a pair of 

 ilaljelliforni divaricator impressions {(l.v) ; in the dorsal valve two 

 pairs of occlusor scars («.«, j;.rt) are well marked, and accessory 

 posterior occlusor scars are traceal)le in some specimens. The 



Fig. 333. — Productus giganteus. (After Woodward.) Carboniferous Limestone. A, 

 Interior of dorsal valve. B, Interior of ventral valve. C, Transverse section of valves. 

 D, Hinge line of A: a, occlusor scars ; d, divaricator scars : ;', "reniform impres- 

 sions " ; ca, cardinal process ; h, hinge line ; jh brachial prominence ; s, cavity 

 for spiral arms ; du, dorsal valve ; re, ventral valve. 



vascular sinuses (r..s) and genital areas are conspicuous in many 

 species of this and other genera. 



In Waldlicimia (Fig. 329) a sul)-uml)onal " peduncular muscle " 



