451 
larger than the L. anomala, a remark which will hear out the identification now made, 
hut I ojjine that Moore’s figure of tlie last-named species is magnified, as I have not met 
with a specimen so large, Pseudnviculn anomala is a j)retty shell, and, from the quantity 
in which it occurs and its glistening appearance, forms an attractive specimen in any 
cabinet. I do not find any difference in the size of the valves, so it was probably 
cquivalve, as Moore says. 
Loc. and Horizon. Wollumbilla {The late Rev. W.R. Clarice ; G, S-weet — Colin. 
Sweet, Melbourne) ; Marauoa Kiver, half a mile above Mitchell Railway Station {B. L. 
TacF) ; Marauoa (Q. Sweet — Colin. Sweet, Melbourne). 
PsEunAvicuLA At^STEALis, Moove, sp., PI. 24, figs. 7, 9, 10, 12, and 1.3. 
Lucina? australis, Moore, Quart. Journ. Geol. Soo., 1870, xxvi., p. 251, t. 14, f. 5. 
Avicida orbicularis, Hndleaton, Geol. Mag., 1884, i., p. 341, t. 11, 1. 10. 
Pseudavicula anomala (paru.), Hudleston, Geol. Mag., 1890, vii. (3), p. 244. 
Sp. Char. Shell generally meleagriniform in outline, unequally orbicular, and 
possessing but little convexity of valves. Dorsal margin short, straight on the posterior 
side, involute on the anterior side, with a byssal sinus of moderate size ; anterior 
margin obliquely and sharply cut off above, rounded below; ventral margin fully 
rounded; posterior margin sub-truncate, obliquely inclined upwards; posterior wing 
small, rather flattened, angle rounded. Umbones slightly more anterior than posterior. 
Small and sharp, but depressed. Adductor scar almost central, large, longitudinally 
elongated and bearing crescentic impression,?. Surface sculpture as in the preceding 
species, but less . sharply defined. 
Obs. P. amtralis is decidedly larger than that I take to be P. anomala, 
and although the sculpture is of the same type, it is never, so far as my experience 
goes, so sharp and regular. The test of P. australis must have been very thin, as it is 
seldom actually preserved. The only hinge structure so far made out is a simple 
involution of the dorsal magin (PI. 24, fig. 12) in which the ligament was placed. 
The shell figured by Mr. Hudleston as Avicula orbicularis is without doubt 
identical with the present species. I am convinced of this after comparing the type at 
the Natural History Museum with numerous other specimens collected by Mr. H. Y. L. 
Brown in South Australia. 
Prof. Ralph Tate would appear to refer* Hudleston’s Avicula orbicularis to 
Maccoyella Barlclyi, Moore ; but in so doing he is clearly wrong, their structure being 
quite distinct. 
Loc. "Wollumbilla {The late Rev. W. B. Clarice ; G. Sweet — Colin. Sweet, Mel- 
bourne) ; Maranoa River {G. Sweet — Colin. Sweet, Melbourne) ; Coottanoonna, S* 
Australia {H. T. L. Brown — Colin. Brit. Mus., London) ; Lake Eyre District {Prof. 
R. Tate— Colhx. Adelaide University). 
Genus — AIACGOYELLA, gen. nov. 
Gen. Char. Shell oval, or orbicular, inequivalve, inequilateral, slightly produced 
obliquely at times, and with a flattened, sub-truncate, or slightly emargiuate posterior 
ond in both valves. Valves plano-convex, slightly concavo-convex, or more or less 
bi-eonvex. Anterior end sometimes more or less lobate. Cardinal margin straight 
on the p)osterior, but oblique on the anterior side. Hinge much thickened and 
strongly grooved for cartilage attachment in both valves; in the right or generally 
non-convex valve the hinge is strongly inflected or folded inwards at or anterior 
^0 the umbo, producing a deep, narrow, and obliquely directed byssal sinus; in 
* Proo. Austr. Assoc. Adv. Sei. for 1888 [1889], i., p. 230. 
