42 
1847 . — In November, 1847, appeared the concluding part of Sir 
Frederick McCoy’s paper on “ The Fossil Botany and Zoology of the Bocks 
associated with the Coal of Australia.” lie recorded Em'ydesma cordata, 
Mor ris, from Arthur’s Hill, N. S. Wales, without comment.' 
✓ 
1849 . — -The fully illustrated work emhodying the geological results of 
the Wilkes American Exploring Expedition, by Dana, appeared about this 
time. In this amplification of the papers already published in the “ American 
Journal of Science ” Dana corrected Morris’ description of Eiirydesma,' 
pointing out that it was rather inequivalved than equivalve, and giving other 
interesting morphological details, Avhich Avill be referred to later, 'fhe two 
species, E. glohosa and E. elliptica, already described by him are retained, 
Fachydomus sncciilus, JMcCoy, as in the second paper of the aboA^e-mentioned 
series, is referred to Eurydesma, and E. cordata, Morris, is discussed. In 
speaking of the genus, Dana says “ there are some analogies to the shell of 
Rippopus and also to that of a MeleayrinaF 
Eurydesnia, elliptica from Harper’s Uill, is a moderately thick, evenly 
convex, elliptical shell, Avith faint concentric lines of growth. E. glohosa is 
a small shell, and is described as being A'ery thick, ventricose and orbicular — 
it is said to haAm come from the “ District of IllaAA^arra,” but Ave believe this 
to be a mistake. E. sacculus, McCoy, sp., Avas described by McCoy as a 
Fachydomus ^ According to Dana, it “ is much thicker than the glohosa, 
as the glohosa is thicker than the elliptica. It is also distinguished by 
its flattened lateral surface aiid slightly excavate lower margin ” ; in other 
Avords, there is evidence of a cincture more apparent in the figure than the 
description Avould lead one to helieve. In McCoy’s figure this is hardly, if 
at all, j)erceptible, and there ap])ears to be considerable doubt as to Avhether 
E. sacculus, Dana, and F. sacculus, McCoy, are one and the same. Dana 
gives Harper’s Hill as the locality of his species and F. glohosus, McCoy 
records from Black Head or IVollongong, localities in the IllaAA’arra District 
the former from the LoAver Marine Series, the latter from the Upp(n’ — thetAvo 
series have hardly any species in common. Eurydesma cordata, Morris, 
Dana says, is a “ much thinner species ” than E. sacculus, and “ from either 
of the preceding it is distinguished by its radiations and slightly flattened 
* McCoy — Ann. Mag. Nat. Hist., 1847, XX, p. 299. 
^ Dana in AA’^ilkes — U.S. Kxplor. Exped., X(Oeol.), 1849, pp. 699-791. 
* McCoy — Auu. Mag. Nat. Hiak, 1847, XX, p. 301, I’l. XIV, fig. 5. 
