ORDER IV TELOTREMATA 331 
a large pedicle opening common to both valves. In the dorsal valve there 
is a high vertical plate to which are attached the descending branches ; 
ascending branches not represented. Recent. 
Ismenia, King. Coarsely plicate shells with the loop consisting of 
fimbriate descending branches and simple ascending branches. Jura. 
Muehifeldtia, Bayle (Megerlea, King), (Figs. 558, 559). Jura to Recent. 
Frenulina, Dall. Sub-genus of Iuehlfeldtia. Recent. 

Fic. 560, 
A, B, Kingena lima, Defr. Cretaceous; England. Lateral and frontal aspect of loop, enlarged (after 
Davidson). C, Specimen from the Galeritenplaner of Salzgitter, 1/;. D, External surface, enlarged. 
E, F, Kingena Friesensis, Schriifer sp. Upper Jura; Gruibingen, Wiirtemberg. 1/;. (c, Crura; d, Dental 
sockets ; e, Jugum ; f, 1, Ascending and descending branches of loop; j, Cardinal process ; 7, Point of recurva- 
ture of loop; S, Median septum). 
Terebratalia, Beecher. Shell when adult like Terebratella, but passing 
through a quite different series of metamorphoses. Recent. 
Dallina, Beecher. Elongate Terebrataliae with a small cardinal process 
and a ventral median sinus. ‘Tertiary to Recent. 
Macandrevia, King. Elongate Terebrataliae with dental plates and no 
cardinal process. Recent. A sub-genus of Hudesia, according to Dall. 
Laqueus, Dall (Frenula, Dall). Like Terebratalia, but the loop has two 

~ KR 
Fic. 561. See a 
, A, Trigonosemus elegans, Defr. White Chalk; 
Lyra Neocomiensis, Orb. Lower England. Interior of dorsal valve, enlarged (after 
Cretaceous ; Morteau, Doubs. Natural Davidson). B, T. Palissyi, Woodw. Upper Cretace- 
$1ze. ous ; Ciply, Belgium. 1/;. (Drawn from nature.) 
lateral processes connecting the ascending and descending branches. Recent. 
Kingena, Davidson (Kingia, Schoenbach), (Fig. 560). Cretaceous ; Europe 
and North America. 
Lyra, Cumberland (Terebrirostra, VOrbigny), (Fig. 561). Cretaceous ; 
Europe. 
