BRACHIOPODA. 179 



gg. Striaeor plications extending from umbo to front of shell, fff. 

 fff Pedicle valve the larger with more prominent umbo. ***. 



*** Radiating plications very few and broad 2 // . 



2 // Umbo of pedicle valve strongly overarching. 

 LXVIII. Clorinda. 

 l f/ Umbo not overarching. 



LXVII. Pentamerus. 

 *** Radiating plications numerous and prominent. 3 // . 

 3 // Spondylium only in pedicle valve. 



LXXII. Camarophoria. 

 3 // Spondylium in pedicle and brachial valve 



( cruralium ) a n '. 



a // Umbo of pedicle valve closely incurved 

 against the brachial. 



LXVIII. Clorinda. 

 a" Umbo of pedicle valve projecting above 



the brachial i /// . 



l /// Sinus, when present, on brachial 

 valve and fold on pedicle. 



LXX. Gypidula. 

 l /// Sinus on pedicle valve and fold on 

 brachial.. LXIX. Pentmnerella. 

 fff Brachial valve the larger. Both umbos very closely 

 incurved, that of the brachial valve the more prom- 

 inent LXIV. Anastrophia. 



99. Sinus or fold absent hh. 



hh. Shell with radiating plications tttt- 



ffff Plications few and broad LXVII. Pentamerus. 



fttt Plications numerous ■**•** 



**** Plications angular LXXII. Camarophoria. 



**** Plications round 4 // . 



\ ff Spondylium in pedicle valve. 



LX V. Conch idium . 

 4 // Spondylium in both pedicle and brachial 



valves LXX. Gypidula. 



hh. Shell with radiating striae, very fine plications or smooth. 5f. 

 5f Pedicle valve with a spondylium. LXXI. Amphigenia. 

 5f Pedicle valve without a spondylium. 



LXXXVIII. Rensselceria. 



h. Shell with small area and with radiating striae or plications OOO. 



000. Area on both valves, nearly equivalve. LXVI. Stricklandinia. 

 000. Area on pedicle valve, which is the larger and has overarching 



umbo ii. 



ii. Sinus on brachial and fold on pedicle LXX. Gypidula. 



ii. Sinus on pedicle and fold on brachial valve. 



LXIX. Pentamerella. 



Shell rhynchonelloid — Length and breadth sub-equal. Cardinal areas 



rarely present. Umbo not prominent, becoming abruptly pointed 



(i. e.. forming a concave line from beak to greatest width of shell). 



Beak usually closely incurved, generally not truncated by foramen. 



