BBICHIOPODA. 371 



interior ; whilst in several others there are but two brachial 

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

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

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



DistHlution, 1 species. Mediterranean. 



Fossil, 34 species. Trias — : Europe. 



? Stpjxgocepiialus, Defrance. 



Etymology, Strinx {sirinfjos), an owl, cepliale, the head.* 

 Tij^pe, S. Burtini, PI. XV., Fig. 13. Figs. 166, 167. Devonian, 

 Euroj^e. 



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 {j) very promi- Fig- I67.t 



nent, sometimes touching the opposite valve, its extremity 

 forked to receive the ventral septum [v s) ; hinge-j)late {]/) suji- 

 porting a shelly loop, after the manner of Argiope. 



Family II. — Spirifeeid^. 



iS/ie?Z 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 cirri, especially on 

 the front of the whorls ; valves articulated by teeth and 

 sockets. 



Spieifeea, Sowerby. 



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



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

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



middle ; the dotted lines proceeding from its inner edge are added from a drawing by 

 M, Suess, and represent wliat he regards as shelly processes for supporting a mem- 

 branous disk. They may be portions of spirals, whose outer whorls are confluent. 



* Internal casts of I^oductus giganteus are called ♦' owl-heads " by quairymen in 

 the North of Eng and. (Sowerby.) 



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

 p, pseudo-deltidium. 



