nnAriiioi'ODA. 97 



Terehratuln pcctiiiiforniis. Biic/i, Ter. p. fi."). t. .'{. f. 'M. 



lirutui, LHh. I). (\:r2. t. ;io. f. 5. 



Rcpincr, Krcifl. j). 41. 



Qimist. Unmlh. p. AiV.^. t. .'H?. f. 14 (not 12, 1.3). 

 TiTcbratula Ililseaiia. Ihemer, Oul. ii. ]). 20. t. IS. f. !^ ; Kr. p. 41. 

 Fossil. (/. Chalk. Maestriclit. 



.3. Trigonosemus Palissii. B.M. 



Shell ()rl)irular, depressed, radiately plaited ; ]tlaits numerous, 

 intcrcalatiii<r ; niarf^ins crenulated ; dorsal valve sliprhtly coneave, 

 siniiati'd in front ; liin^e-line curved, narrower than the shell ; 

 cardinal process prominent; loop doubly attached ; ventral valve 

 convex ; beak ])rominent, curved, with a minute apical foramen; 

 hitige-areii.lar<;t', triangular, concave, sharply bordered; deltidium 

 large, triangular, tlat. Lon. 7i, lat. 7, alt.3 lines. 



TerebratcUa Palissii, Woodward, 1852, Miis. Brit. 

 Trigonosemus ]inlciiellus (not Nilsson), Dai\ Ann. Nat. Hist. 



June 18o0, ])1. 15. f. 4 (incorrect). 

 Terebratula pulchella (part.), Quenst. Handb. t. .':i7. f. 12, 13? 

 Fossil. Upper Chalk. Ciply, Belgium. 



4. Trigonosemus pulchellus. B.M. 



Shell suborbicular, depressed, radiately plaited ; plaits inter- 

 calating ; dorsal valve slightly concave, truncated at the hinge- 

 line ; rp«/rfl/ valve convex, with a prominent, incurved and sharp- 

 edged beak; hinge-area large, triangidar, concave; foramen apical, 

 minute ; deltidium large, triangular, flat ; loop elongated, re- 

 flected, attjiched to a septum which reaches the opposite valve. 

 Lon. 7, lat. 6, alt. 2 lines. 



Terebratula pulchella, Nilsson, 1827, Petref. Sues. p. 36. pi. 3. 

 f. 14. 



Reenter, Kreid. p. 41, 

 Dalman, Vet. Akad. p. 138. 

 Fossil. Upper Chalk. Sweden. 



5. Trigonosemus incertus. 



Shell elongated, oval, striated ; valves almost equally convex ; 

 beak produced, rounded, moderately recurved ; area triangular, 

 nearly flat, short ; foramen small, oval ; deltidium bordering a 

 small portion of the foramen ; striae about 34, frequently 

 intercalated, and decussated by numerous, fine, concentric lines 

 of growth. Lon. 41, lat. 4, alt. 2^ hnes. 



Trigonosemus incertus, Davidson, Mon. Cret. p. 31. pi. 4. f. 5. 

 Fossil. Lower Chalk {Craie chloritee). Chard, Somerset. 



F 



