Discorevji of <i Spsm'/c < '(niiihirlfi . — Buedemrnin. 71 
appenclages show both, the connecting film and the central 
cup bulging inward. These observations can, in the opinion 
of the writer, be only accounted for l)y the assumption that 
tlie basal a])pendage was an organ of attachment by suction. 
Explanation of Plate II. 
Coniilavia (/nicilis Hall. Utica shale, Dolgeville, N. Y. 
Fig. 1. Dorsal view of basal appendage. Enlargement of the append- 
age of the specimen reprocUiced in pi. IX, fig. 1. XlO. 
Fig. 2. Vertical section through appendage. Whole specimen as 
found. XlO. 
Fig. .3. Nearly vertical section, a, basal ring of exterior bell, seen 
from inside: b, dorsal part of bell; c, interior cup. XlO. 
Fig. 4. Detached specimen of CoH?(/r<r?V/ (/roc«^/.s, bearing the append- 
age reproduced by fig. 3. Nat. size. 
Fig. o. Underside of appendage, a, base of exterior bell: h, base of 
interior cup. xlO. 
Fig. G. Ventral view of appendage, onh^ the bases of exterior bell (o) 
and interior cup (b) being preserved. XlO. 
Fig. 7. Ventral view of appendage, a, ba.se of exterior bell: J), base 
of interior cup. XlO. 
Fig. 8. Ventral view of appendage, showing the radial furrows of the 
base of the exterior bell and the concentric structure of the latter. XlO. 
Fig. 9. Lateral view of basal appendage, a, dome of bell: b, basal 
ring of bell: c, impression of ba.se of bell: d, impression of basal skin: 
e, node in center, cast of central cup. XlO. 
Fig. 10. Interior view of bell from ventral side, shows wrinkled dome 
of bell and subquadrangular entrance of pyramid of Counlaria. XlO. 
Fig. 11. Counterpart of the preceding. Shows the apex of the pyra- 
mid. XlO. 
Fig. 12. Dorsal view of appendage. Dome of bell Ijroken away. XlO. 
Fig. 13. Ventral view of appendage. Shows radial slriation of base 
of bell. XlO. 
Fig. 14. Comdaria gracilis Hall attached to a fragment of Stict(>p<i- 
rella. Nat. size. 
Fig. 15. The same. Basal appendage as found originally. X8. 
Fig. 16. The same. Matrix removed by acetic and hydrofluoric acids. 
a, interior bell: h, impression of connecting V)asal skin: c. impression of 
central cup. X8. 
Fig. 17. Ventral view of appendage. Exterior bell seen in section. 
Exhibits apex of pyramid. X6. 
Fig. 18. Ventral view of ajjpendage. (/. base of bell: /*. base of cen- 
tral cup. XlO. 
Fig. 19. Impression of basal appendage. Junction of two marginal 
grooves of pyramid preserved. XlO 
Fig. 20. Transversal section through appendage. Shows the four 
marginal grt)oves of the shell of Couiihn-itt in .section. XlO. 
Fk;. 21. Diagrammatic section through l)asal appendage. The dotted 
part is a section through the basal appendage in the state of compres- 
sion, the striated through the same in the state of attachment. XlO. 
