51 
SERPULA prismatica. 
TAB, DCXXXIV. — -Jig. 5. 
Spec. Char. Linear, four-sided, minute ; lines of 
growth strong, bent acutely over the angles. 
Syn. Vermilia angulata, Morris, Catal. 67. 
Although the fragment of this shell be very imperfect, 
it is easily distinguished as a species by its square form. 
Discovered in the clay at Chalk Farm by Mr. Wetherell, 
whose patient attention to the minute fossils of the London 
clay is so well known. 
SERPULA trilineata. 
TAB. DCXXXI V.—Jig. 6. 
Spec. Char. Linear, attached throughout, tor- 
tuose, minute ; attached surface broad ; on 
the back are three slightly elevated keels. 
Syn. Vermilia trilineata, Morris, Catal. 67. 
Fixed upon Terebratula striatula, found at Chalk Farm 
by Mr. Wetherell. 
SERPULA heptagona. 
TAB. DCXXXI V.—^g. 7. 
Spec. Char. Cylindrical, with seven keels ; free 
except near the apex, where it is conical, with 
3 to 5 keels curved and attached ; lines of 
growth strong; keels often expanded into 
variously undulating wings. Operculum fun- 
nel-shaped, its disc radiated. 
