BRACHIOPODA. 371 



interior ; whilst in several others there are but two brachial 

 lobes. The Liassic species form the subject of a monograph by 

 M. Eudes Deslongchamps ; they are often minute, and attached 

 in numbers to sea-urchins, corals, and terebratulse. 



Dlstrilution, 1 species. Mediterranean. 



Fossil f 34 species. Trias — . Europe. 



? Stringocephalus, Defrance. 



Etymology, Strinx {stringos), an owl, cephale, the head.* 

 Type, S. Bui'tini, PI. XV., Tig. 13. Pigs. 166, 167. Devonian, 

 Europe. 



Shell punctate; sub-orbicular, with a prominent beak; ventral 

 Valve with a longitudinal septum {v s) in the middle ; hinge* 

 area distinct ; foramen large and angular in 

 the young shell, gradually surrounded by 

 the deltidium, and rendered small and oval 

 in the adult ; deltidium composed of three 

 elements ; teeth prominent ; dorsal valve 

 depressed, cardinal process (./) very promi- Fig- I67.t 



nent, sometimes touching the opposite valve, its extremity 

 forked to receive the ventral septum {v s) ; hinge-plate {p) sup- 

 porting a shelly loop, after the manner of Argiope. 



Eamily II.— Spiriferid^. 



Shell furnished internally with two calcareous spiral processes 

 (apophyses) directed outwards towards the sides of the shell, and 

 destined for the support of the oral arms, which must have 

 been fixed immovably; the spiral lamellce are sometimes 

 epinulose, indicating the existence of rigid ciiTi, especially on 

 the front of the whorls; valves articulated by teeth and 

 sockets. 



Spirieeea, Sowerby. 



Type, S. striata, Sby., Fig. 168. 



Synonyms, Trigonotreta. Konig. Choristites, Fischer. Del- 

 thyris, Dalman. Martinia, &c., M'Coy. 



middle ; the dotted lines proceeding from its inner edge ai-e added from a drawing by 

 M. Suess, and represent what he regards as shelly processes for supporting a meui- 

 branous disit. They may be portions of spirals, whose outer whorls are contluent. 



* Intenial casts of I'Yoductus giganteus are called " owl-heads " by quarrymen in 

 tlie North of Eng and. (Sowerby.) 



t Fig. 167. Young shell, magnified four diameters; A, hinge area; b, deUidium; 

 p, pseudo-deltidium. 



