316 MOLLUSCOIDEA—BRACHIOPODA SUB-KINGDOM V 
Lacazella, Munier-Chalmas (Figs. 525, 526). Dorsal brachial impressions 

Fic. 526. 
Lacazella . Mediter- 

Fic. 524. : Aca 
ranea, Risso. Recent. 
Thecidea papillata, Schloth. Upper Lacazella vermicularis, Interior of dorsal 
Cretaceous; Ciply, Belgium. A, B, In- Schloth. sp. Upper Creta- valve showing 
terior of ventral and dorsal valves, re- _ ceous; Maestricht. Dorsal brachia, 2/; (after 
spectively, 2/; (after Woodward). valve, 2/; (after Suess). 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 

Fic. 527. Fic. 528. 
Thecidiopsis digitata, Goldf. Greensand; Essen on the Pterophloios Emmrichi, Giimbel. 
Rhine. A, Dorsal aspect. B, C, Interior of ventral and Rhaetic ; Kossen, Tyrol. In- 
dorsal valves, respectively, 1/;. terior of dorsal valve, 1/;. 
impressions have three pairs of simple lobes antero-laterally directed. Jurassic; 
Europe. 
Pterophloios, Giimbel (Bactrynium, Emmrich), (Fig. 528). Dorsal brachial 
impressions with about ten laterally directed lobations. Alpine Rhaetie. 
Davidsonella,. Munier-Chalmas. Elongate shells with the long, narrow, 
dorsal, brachial 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 two 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. 
