316 MOLLUSCOIDEA BRACHIOPODA SUB-KINGDOM v 



Lacazella, Munier-Chalmas (Figs. 525, 526). Dorsal brachial impressions 



FIG. 524. 



Thecidea papillate, Schloth. 

 Cretaceous; Ciply, Belgium. A, B, 

 terior of ventral and dorsal valves, re- 

 spectively, 2 /i (after Woodward). 



FIG. 525. 



Lacazella vermicularis, 

 Schloth. sp. Upper Creta- 

 ceous ; Maestricht. Dorsal 

 valve, 2/j (after Suess). 



FIG. 526. 



Lacazella Me. 'I ltd 

 ranea, Risso. Recent- 

 Interior of dorsal 

 valve showing 

 brachia, 2/j (after 

 Woodward). 



with two or three unequal pairs of lobes, medially directed. Jurassic to 

 Recent ; Europe. 



Thecidiopsis, Munier-Chalmas (Fig. 527). The two, large, dorsal, brachial 

 impressions each have four pairs of lobes laterally and medially directed. 

 Cretaceous ; Europe. 



Thecidella, Munier-Chalmas. Dorsal brachial impressions simple, anteriorly 

 directed. Jurassic ; Europe. 



Eudesella, Munier-Chalmas. Transverse shells in which the dorsal brachial 



FIG. 527. 



Thecldiopais digitata, Goldf. Greensand ; Essen on the 

 Rhine. A, Dorsal aspect. B, C, Interior of ventral and 

 dorsal valves, respectively, 1/1- 



FIG. 52S. 



Pterophloios Emmrichi, Giimbel. 

 Rhaetic ; Kossen, Tyrol. In- 

 terior of dorsal valve, 1/1- 



impressions have three pairs of simple lobss antero-laterally directed. Jurassic; 

 Europe. 



Pterophloios, Giimbel (Bactrynium, Emmrich), (Fig. 528). Dorsal brachial 

 impressions with about ten laterally directed lobations. Alpine Rhaetic. 



Davidsonella, Munier-Chalmas. Elongate shells with the long, narrow, 

 dorsal, brachia] impressions simple and antero-laterally directed. Jurassic ; 

 Europe. 



Family 6. Productidae. Gray. 



Strophomenacea with hollow anchoring spines, Silurian to Permian. 



Chonetes, Fischer (Fig. 529). Shell transversely elongate, semi-circular in 

 outline, normally 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 tw r o broader lateral grooves. Brachial impressions 

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

 rarely smooth or concentrically rugose. Silurian to Permo-Carboniferous. 



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

 posed to be without cardinal spines. Lower Devonian. 



