470 
Nucula, sp. ind. 
Ohs. Another species, apparently differing from any of the foregoing, has been 
obtained duriug the sinking of the Aramac Well. It is only known in the condition of 
an internal cast ; but this is trigonal, with a semi-pointcd posterior end, a straight 
posterior hinge, and numerous small teeth. The muscular impressions are strongly 
marked, the anterior being situated low down, whilst a single row of dot-like .scars 
(refractor impressions?) are ranged from the umbonal cavity to the posterior adductor. 
The margins are apparently plain. 
A very similar shell to this is JSTuoula planimarginata, Meek,* from the Fox 
Hills Group, of the Missouri Cretaceous. 
In form this species is not unlike JV. peoiinata, Sby., of the European Gault, but 
we know nothing of the ornament as a further means of comparison. 
Log. Aramac Well, at two hundred and forty-four feet deep (S'. Sharwood). 
Family— TEIG ONIAD/E. 
Genus — IRIGONIA, Bruguiire, 1789. 
(Encycl. Method., i., PI, 14.) 
Teigonia LiNEAXA, Moore. 
Myophoria, sp,, McCoy {Jide Moore), Trans. R. Soc. Viet., 186-3, vi., p. 44. 
Trigonia lineata, Moore, Quart. Journ. Geol. Soc., 1870, xxvi., p. 25.3, t. 13, f. 12. 
,, ,, Lyoett, Mon. Brit. Foss. Trigonise, 1879, No. 5, p. 224. 
Sp. Char. Shell thick, equivalve, inequilateral, gibbous, as broad as long ; 
umbones convex, recurved towards the anterior margin ; anterior side and ventral 
margin rounded ; posterior angle somewhat rounded ; marginal carlua) absent ; shell 
gradually sloping to the front; surface with close-set regular transverse concentric 
striae; about twenty in number, which on the anterior margin possess depressed 
tubercules. {Moore.') 
Ohs. Mr. Moore was the first to point out that McCoy’s Mgophoria was in 
reality a Trigonia, and he, in accordance with this vio3V, proposed for it the above name, 
comparing it wdth the European Portlaudian species, Trigonia gibbosa. It was from the 
supposed presence of this Mgophoria that McCoy suggested the occurrence of the Eha;tic 
Formation in Australia, but it “ does not possess the oblique keel and the acute 
posterior side ” of that genus. 
It is more than likely that the late Dr. Lycott was correct when ho compared 
T. lineata with the Indian Cretaceous species T. oricnialis, Forbes,t and T. suborbicularis, 
Forbes, J rather than to an Oolitic species, as suggested by Moore. In fact, Lycett 
believed T, lineata to have a strongly Cretaceous aspect. 
Log. Wollumbilla {The late Rev. W. B. Clo/rJce). 
Teioonia mesembeia, Ten. Woods. 
Trigonia rnesembria. Ten. Woods, Proo. Liun. Soc. N. S. Wales, 1883, viii., Pt. 2, p. 237, t. 12, f. 1-3. 
Sp. Char. Shell ovately oblong, tumid, very convex; umbones somewhat anterior, 
not recurved ; superior border moderately convex, rather elongate ; posterior border 
curved, slightly truncate at the siphonal margin ; anterior border tumidly produced and 
rounded ; posterior groove wide, conspicuous, shallow, widening rapidly from the 
umbones to the margin ; costas irregular, not prominent, some smaller ones occasionally 
intercalated, all passing horizontally across the valve, slightly undulating anteriorly, 
* Report XJ.S. Geol. Survey Ter., 1870, ix. (Invert. Cret. Tert. Foss. Up. Missouri), t. 15, f. 8a-h. 
t Trans. Geol. Soc., 2nd Ser., vii., p. 1.30, t. ISj f. 11. 
t Ibid., p. 150, t. 18, f. 10. 
