176 
Spirifer crebristria, J. Morris} 
(Or Spirifer lineatus, W. Martin, varietas ?) 
PI. IX, Pig. 5. 
Spirifer {Terehratula ?) crebristrla, J. Morris, 1845, in Strzeleclci’s Phys. Descr. N. S. 
Wales and V. D. Land, p. 279, pi. 15, fig. 2. 
Spirifera {^eticularia) crehristria, P. McCoy, 1847, Ann. Mag. Nat. Hist., XX, p. 232. 
This shell is transverse, elliptical, and slightly ventricose. The ventral 
valve has a broad, shallow, ventral furrow, to which on the dorsal valve 
corresponds an imperfectly developed dorsal ridge, becoming apparent only 
by the sinuosity of the base. The whole surface of the internal cast is orna- 
mented by numerous fine, radiating, rather deep strim, bifurcating at intervals, 
and keeping the same diameter throughout their length. These strim are 
crossed by numerous concentric undulations of growth, producing a reticu- 
lated design. 
Dimensio}is.=—T\\Q length is thirty and the breadth thirty-eight milli- 
metres. 
Relations and Differences. — This Spirifer is extremely like S. ellipticus, 
J. Phillips, which is only a variety of S. lineatus, Martin, the radiating 
stria3 of which become apparent when the test is partly removed. Again, as 
all the specimens sent me are internal casts, the muscular impressions of which 
are only partly visible, I am very much inclined to think that S. crehistria, 
Morris, is also only a variety of S. tinea, tus, Martin, in which, owing to special 
circumstances, the longitudinal strise are better and more regularly developed. 
I am the more encouraged to hazard this opinion by the fact that one of the 
specimens of S. lineatus just described by me shows, on a small part of its 
surface, where the shell is removed, the radiating longitudinal strim which 
form the chief characteristic of S. crehristria, J. Morris. Nevertheless, as I 
have seen on no European specimen the characteristic I have just described 
as on the Australian specimen, I have retained to the variety described by 
Mr. J. Morris the name under which the learned Paleontologist has figured it. 
Dorizon and Localities. — The specimen described by Mr. Morris 
was found at Booral. Mr. McCoy says the species is rather rare in the shales 
* [Relicularia crehristria, — A. H. Foord, Geol. Mag., 1890, VII (3), p. 153. — W.S.D.] 
