96 
BRACHIOPODA. 
Terebratella subpentagona, Koch, 1837, Beitr. zur Kenn. Ool. 
p. 21. pi. 1. f. 8. 
D’Orb. Prod. i. p. 221. 
Fossil. Lower Lias. Germany. 
5. TRIGONOSEMUS. 
Shell plaited, beak produced, curved, uith a narrow apical 
foramen ; area large, triangular, flat, marked by tbe outline of 
the flat deltidium ; cardinal process very prominent. 
Trigonosemus (elegans), Konig, 1822, leones Foss. p. 3. f. 73- 
Davidson, 1852, Mon. Cret. p. 28. 
Delthyridaea (pectiniformis), M‘Coy, 1845, Griffith's Irish Garb. 
Fossils (unpublished). 
Fissurirostra (recurva), D’Orb. Ter. Cret. iv. p. 133. t. 520 ; Ann. 
Sc. Nat. 1848. 
Fissu’ostra, D’Orb. 1849, Cours Elem. Paleeont. p. 89. 
1. Trigonosemus elegans. B.M. 
Shell oval, striato-costate ; striae 30-40, often intercalated; 
dorsal valve slightly convex, longitudinally depressed in front ; 
beak much produced, rather recurved ; area very large, trian- 
gular, nearly flat ; foramen small and narrow, apical ; loop elon- 
gated, reflected, doubly attached ; cardinal process very promi- 
nent. Lon. 11, lat. 9, alt. 5 lines. 
Trigonosemus elegans, Konig, 1825, leones Foss. p. 3. pi. 6. 
f. 73. 
Davidson, Mon. Cret. p. 29. pi. 4. f. 1-4. 
Terebratula elegans, Defr. 1828, Diet. Sc. Nat. hii. p. 157. 
Terebratula recurva, id. p. 161. 
Fissurirostra recurva, elegans, et pectita, D’Orb. 1847, Ter. Cret. 
iv. p. 133-136. t. 520. 
Fossil. Chalk. England (Norwich) ; Belgium (Ciply) ; France. 
2. Trigonosemus pectiniformis. B.M. 
Shell trapezoidal, depressed, radiately ribbed; ribs straight, 
dichotomous ; ventral valve elevated in the middle, dejiressed at 
the sides ; beak recurved ; area nearly as wide as the shell, deep, 
sharply margined; deltidium triangular, flat; foramen minute, 
apical ; dorsal valve triangular, depressed in the centre ; cardinal 
jirocess prominent ; loop elongated, reflected, doubly attached. 
Lon. 6, lat. 6, alt. 3 lines. 
Terebratuhtes pectiniformis, Schlotheim, 1813, Taschb.vn. p. 113. 
