ORDER IV TELOTREMATA 327 
Jucavella, Bittner. Small, smooth, biconvex shells, with a very short 
Centronella-like loop. Alpine Trias. 
Nucleatula, Bittner. Like Juvavella, but having a longer loop with a well- 
developed and fimbriated vertical median plate. Alpine Trias. 
Dinarella, Bittner. Alpine Trias. Chascothyris, Holzapfel. Devonian ; 
Germany. 
Family 2. Terebratulidae. Gray. 
Terebratulas developing originally a Centronella-like loop, and thence by @ short 
series of metamorphoses resulting at imaturity in a free loop of varying form. 
Devonian to Recent. 
Sub-Family A. SiRINGOCEPHALINAE. Dall. 
Terebratulidae with a long loop, following the margin of the dorsal valve, not 
recurved in front. Probably no median coiled arm. 

Fic. 548. 
Stringocephalus Burtini, Defr. Devonian; Paffrath, near Cologne. 4, Side-view, 2/3 natural size. B, Greatly 
reduced diagram showing brachidium and median septa. C, Young specimen with large delthyrium and deltidial 
plates. D, Interior of dorsal valve, natural size, paitly restored (a, Adductors ; c, Crura; d, Dental sockets ; 
l, Loop; pr, Cardinal process ; s, Median septum). 
Stringocephalus, Defy. (Fig. 548). Devonian; Europe and North America. 
Sub-Family B. MEGALANTERINAE. Waagen. 
Terebratulidae with a long loop giving off ascending branches. Devonian to 
Carboniferous. 
Megalanteris, Oehlert (Meganteris, Suess). Large, smooth, equally biconvex, 
sub-oval shells, with the long convergent jugal processes of the loop extending 
beyond the connecting band of the ascending branches. Devonian ; Europe 
and North America. 
Cryptonella, Hall. Elongate oval shells with short jugal processes. 
Devonian to Lower Carboniferous ; North America, England, and Bohemia. 
