CLASS II 



BRACHIOPODA 



389 



Pterophloios Giimbel (Badrynium Emmrich) (Fig. 577). Dorsal brachial 

 impressions with about ten laterally directed lobations. Alpine Khaetic. 



Davidsonella Munier-Chalmas. Elongate shells with 

 the long, narrow, dorsal, brachial impressions simple 

 and antero-laterally directed. Jurassic ; Europe. 



(?) Cadomella Munier-Chalmas. Lias ; Europe. 



Family 3. Productidae Gray. 



Strophomejiacea with holloio anchoring spines. 

 Ordovician to Permian, 



Fig. 577. 



-P Pterophloios emmriohi Gum- 



Late bel. Rhaetic; Kossen, Tyrol. 

 Interior of dorsal valve, i/i. 



Subfamily A. Chonetinae Waagen. 



Produdids with the few anchoring spines restricted to the ventral cardinal margin. 



Chonetes Fischer (Fig. 578). Shell transversely elongate, semicircular in 

 outline, typically concavo-convex, sometimes plano-convex. Upper margin of 

 cardinal area in ventral valve bearing a single row of hollow spines ; these are 

 prolongations of tubes which penetrate obliquely the substance of the shell 

 along the hinge-line. Teeth strong. Cardinal process of dorsal valve divided 

 by a narrow median and two broader lateral grooves. Brachial impressions 

 more or less distinct. External surface usually covered with radiating striae, 

 rarely smooth or concentrically rugose. Late Ordovician to Permian. Sub- 

 genus : Eodevonaria Breger. Chonetids with denticulate hinge-lines. Lower 

 Devonian ; America and Europe. 



Anoplia Hall and Clarke. Smooth or squamose shells like Chonetes, sup- 

 posed to be without cardinal spines. Lower Devonian ; North America. 



Chonostrophia Hall and Clarke. Like Chonetes, but with the shell reversed 

 or concavo-convex. Lower and Middle Devonian ; North and South America. 



Chonetella Waagen. Upper 

 Carboniferous ; Lidia. Chonetina 

 Krotow. Permian ; Russia. 



(?) DaviesieUa "Waagen. Shell 

 productoid, but without spines 

 and well-developed cardinal area 

 and teeth. Upper Carboniferous : 

 England. 



(?) Aulacorhynchus Dittmar {Iso- 

 gramma Meek and Worthen). Very 

 large, transverse, thin shells with a 

 ventral platform. Exterior surface 

 with numerous, regular, continuous, 

 concentric ridges. Upper Car- 

 boniferous ; Europe and North 

 America. 



Pio. 578. 



A, Chonetes striatellus (Dalm.). Silurian ; Gotland, i/j. 

 B, Interior of dorsal valve (after Davidson). C, C. sar- 

 cmulatus de Kon. Devonian ; Coblenz. i/x. 



Subfamily B. Productinae Waagen. 



Productids with the anchoring spines more or less abundant over the entire ventral 

 and sometimes also over the dorsal valve. 



Produdella Hall. Shells small, productoid, with narrow cardinal areas in 



