406 



MOLLUSCOIDEA 



PHYLUM V 



Fremdina Dall. Subgenus of Muehlfeldtia. Recent. 



Terehratalia Beecher. Shell when adult like Terehratella, but passing 

 through a quite different series of metamorphoses. Recent. 



Dallina Beecher. Elongate Terehrataliae with a small cardinal process and 

 a ventral median sinus. Tertiary to Recent. 



Macandrevia King. Elongate Terehrataliae with dental plates and no 

 cardinal process. Recent. A subgenus of Eudesia, according to Dall. 



Laqueus Dall (Fremda Dall). Like Terehratalia, but the loop has two 

 lateral processes connecting the ascending and descending bi'anches. Recent. 



Fig. 609. 



A, B, Kingena lima (Defr.). Cretaceous ; England. Lateral and frontal aspect of loop, enlarged (after 

 Davidson). C, Specimen from the Galeritenplriner of Salzgitter, i/,. D, External surface, enlarged. E, F, 

 Kingena friesensis (Schriifer). Upper Jura ; Gruibingen, Wiirtemberg. Vi- ^'> Crura ; d, Dental sockets ; 

 e, Jugum ; /, I, Ascending and descending branches of loop ; j. Cardinal process ; r, Point of recurvature of 

 loop ; S, Median septum. 



Kingena Davidson (Kingia Schloenbach) (Fig. 609). Cretaceous ; Europe 

 and North America. 



Pseudokingena Bose and Schlosser. Cretaceous ; Europe. 



Lyra Cumberland (Terehrirostra d'Orb.) (Fig. 610). Cretaceous; Europe. 



Fto. tilO. 



Lyra 7ieocoiniensis (d'Orb.). 

 Lower Cretaceous ; Morteau, 

 Doubs. Natural size. 



A, Trigonogemus elegans Koenig. White Chalk ; 

 England.- Interior of dorsal valve, enlarged (aftei- 

 Davidson). B, T. palissiiiWoodw. Upper Cretace- 

 ous ; Ciply, Belgium, i/j. 



Delthyridea 



King) 



Trigonosemus Koenig (Fissitrirostra, Fissirostra d'Orb. 

 (Fig. 611). Cretaceous,- Europe. 



ilficro</i?yns Deslongchamps (Fig. 612); Ornithella Deslongchamps, ; Zeilleria 

 Bayle. Jurassic genera ; Europe. 



Aidacoihyris'DonVxWii (¥ig. 613). Trias to Cretaceous ; Europe. Eudesia 

 King ; Orthotoma and Trigonella Quenst. ; Flahellothyris Deslong. Jura ; Europe. 



