DAVIDSON — ON SOME FOSSIL BRACHIOPODA. 469 
'33. Atiiyris pl/vno-shlcata, Phillips, Geol. York, vol. ii., pi. x., fig. 15: and 
J):\y., pi. xYi., fig. 2 — 13 and 15 =. oblonga, Sow. = 
paradoxa and ohlusa, M'Coy, 
34. ,, LAMELLOSA, L'Eveillo, Memoires dc la See. Gool. de France, 
vol. ii., p. 11,' figs. 21—23 : and Dav., pi. xvi., fig. 1, and 
■pi. xvii., fig. 5 — G z=. squamosa, Phillips. 
35. „ BXPANSA, Phillips, Geol. of York, vol. ii., p. 220, pi. x., fig. 18 : 
, and Dav., pi. xvi., fig. 14, 16, and 18, pi. xvii. fig.l — 5. 
36. ,, RoissTi, L'Eveillo, Mem. Hoc. Geol. de France, vol. ii., pi. ii , fig. 
18 — 2Q =: fimbriala and glahristria, Phillips = rfcpmsa, 
M'Coy. 
137. ,, GLOBULAEis, Phillips, Geol. of York, vol. ii., pi. x , fig. 22, 
38. ,, SUBTILIT.I, Hall, in Howard's Ex. of the Valley of the great Salt 
Lake of Uta, pi. ii., fig. 1 : and Dav., pi. 21-22. 
39. „ AMBiGUA, Sow., M.C., tab. 376 = sublobata, Portlock =pentaedra, 
Phillips. 
40. Athyeis ? OREGARiA, M'Coy, Synopsis, pi. xxii., fig. 18 : and Dav., pi. xv., 
fig. 27 and 28. I have never had the opportunity of 
studying a perfect example of this shell, and I am even 
uncertain as to its genus. 
41. Retzia kadialis, Phillips, Geol. of York, vol. ii., pi. xii. fig. 40—41, 
Descriptions and figures of all these species and of their varieties will 
be found in the portions of ray work relating to the Carboniferous 
Brachiopoda, published in the volume of the Palscontographical Society 
for the years 1856, 1857, and 1858 ; but as this Monograph cannot be 
completed before two or three years, on account of the great number 
of plates that will be required, the Author will feel greatly indebted 
towards aU those who may feel disposed to assist, by communicating 
their observations and material. 
EXPLANATION OF PLATE XXL 
1. Spirifera striata, Martin, from which a portion of the shell of the smaller 
valve has been removed, in order to show the back of the spiral 
cones, and their attachment. 
2. ,, Schrenkii, Keyserling. Interior of the smaller or dorsal valve, with 
one of the spiral cones in situ, the other having been removed so 
as to expose the muscular impressions. A A, adductor, or anterior 
and posterior occlusor muscle of Hancock. J, Cardinal process, 
to which was attached Mr. Hancock's divaricator, or cardinal 
muscle, t, sockets for the reception of the teeth of the opposite 
valve. 
3. „ Schrenkii, Keyserling. Interior of the larger or ventral valve. D, 
pseudo-deltidium. t, teeth. A, impressions left by the adductor 
or occlusor muscle. R, of the cardinal or divaricator muscle. 
Several instructive fragments of the interior of this species were 
figured and described by Count A. Von. Keyserling in Dr. Schrenk's 
Russian work " die Tundren der Samojeden." 
4. „ Cyrtana, Dalman, interior of the ventral valve. 
5. ,, Anossofi, Vemeuil, ,, ,, 
6. „ Mosquensis, Fischer, „ ,, 
These last three figures arc here drawn to explain modifications 
in the shape and development of the diverging dental or rostral 
plates. 
