DAVIDSON — ON SOME FOSSIL BRACHIOPODA. 
471 
„, „ TT n ^ ") I clo not possess material to enable me to illustrate 
21 rREMATOsriRA Hall ? r genera? but it is to be presumed that Mr. 
22. NucLEOSPiKA, Hall ? | ^^j^^ ^^.^ ^^^^^^ ^^-^ deficiency. 
23. UnciTEs gryphvs, an imperfect representation of the interior of a portion 
of both valves, showing the position of the pouch-shaped expan- 
sion ig), and the attachment of the lamellce, which are supposed 
to have formed the spiral cones. A fragment has been added 
from another specimen, in which are seen traces of spiral 
laraella3 ; but a more perfect representation of these processes, 
and of the muscular impressions in both valves, has still to be 
produced. 
24. 1, gryiilms. Profile view of the same, a portion of the shell having been 
removed, so as to show that the pouch-shaped depressions did 
not communicate with the interior of the shell. 
25- I, gryphus. A specimen to show that in the young state the shell was 
moored to marine objects by the means of a peduncle issuing 
from a perforation or foramen in the beak of the ventral valve. 
26. Ateypa, Dalman — SriRiGEKiNA, d'Orb, reticularis, Linnseus. Interior of the 
dorsal valve, showing the natural position of the vertical spiral 
cones. 
27. „ Interior of the ventral valve, F, foramen ; D, deltidium ; T, teeth ; 
A, adductor or occlusor ; R, ventral adjuster muscular impres- 
sions. 
28. „ Specimen from which the larger portion of the dorsal valve 
has been removed in order to show the back of the spiral cones. 
29. ., Interior of the dorsal valve, from which the spiral lamellce have 
been removed, so as to exhibit the impressions of the ad- 
ductor or anterior and posterior occlusor muscles. 
30. A.voPLOTHECA Imncllosa, Sandberger. Fragment showing the vertical spiral 
cones. 
31. „ Internal cast of the dorsal valve. A, impressions left by the 
adductor or anterior and posterior occlusor muscle ; J, cardinal 
process. 
32. „ Internal cast of the ventral valve. Figures, 30, 31, and 32 are 
taken from Dr. Sandberger's Paper, published in 1855 by the 
Academy of Vienna ; but it is to be regretted that the material 
hitherto discovered has not enabled the proposer of the genus to 
give us a more perfect representation of the spiral appendages. 
33. DAViDSONLi. Verneuilii, Bouchard. Interior of the dorsal valve (enlarged). 
J, cardinal process ; t, sockets ; A, A, impressions left by the 
adductor or posterior and anterior occlusor muscle. A restored 
representation of the spiral lamellae recently discovered by 
Prof, de Koninck has been added on one side. 
34. ,, Verneuilii, Interior of the ventral valve, showing the teeth, pseudo- 
deltidiura, adductor and divaricator muscular impressions, as well 
as the massive cones and vascular impressions. 
35. KoNiNCBiiNA Leonhardi, Wissman. A translucid specimen made thinner by 
acid, and seen from the exterior of the ventral valve, by which 
means the position of the spiral lamellae has become visible. 
36. „ Leonhardi. Interior of the dorsal valve, with a portion of the spiral 
lamello3 preserved. These two illustrations are taken from 
drawings sent me by Prof. Suess. 
Note. — Since the publication of the tenth No. of the Geologist, I have received, 
through the kindness of Mr. Burrow, of Settle, in Yorkshire, a great number of frag- 
ments of Cyrtina septosa, and was happy to find among them the internal cast of the 
