462 
radiating strife became almost ribs, and tlie concentric lines nearly died out. Locality 
appears to have had an influence on the size of the shell ; thus, those at Aramac are 
rather small, those at the Barcoo larger. 
The inner layers of shell have a silhy lustre, with very fine anastomosing, 
concentric lines. A very thin and delicate shell occurs at Blackall Well, which has 
all the surface characters of this species, except that the concentric lines are finer or 
more prominent. It may, perhaps, be a distinct species. 
Log. Hughenden iStation, Flinders Ttiver (T/ie a. Drti'wfrce ; The 'Ron. A. C. 
Gregory')-, Eockwood Station, Landsborough Eiver, in a light-drab shelly limestone 
{Rrof. A. Lioersidge — Colin. Sydney University ; A. L. Lack) ; Flinders Eiver, seven 
miles above Marathon Station, in a dark-drab limestone (A. L. Jack) ; Marathon 
{Q. /Sfireei— Colin. Sweet, Melbourne) ; Neelia Creek, at crossing of the Cloncurry Eoad, 
in a light-drab limestone (A. L. Jack) ; Aramac Well, at a depth of two hundred and 
forty-four feet {8. Sharwood); Coorena Woolshed, twenty-four miles south of Aramac 
(A. L. Jack) ; Stone Hat, Eockwood Creek, Landsborough Eiver, in a drab shelly lime- 
stone ; Landsborough Eiver, five and a-half miles north-north-west of Eockwood Station, 
in a yellow-drab arenaceous limestone; dirking Creek, near its head, in a greenish 
limestone ; Leichhardt Eiver, seven miles from mouth of Gunpowder Creek, in a dense 
cream-coloured limestone (A. L. Jack) ; Warrianna Bore, at three hundred and fifty-one 
feet {J. B. Henderson) ; Barcoo Eiver, right bank, six miles above Northampton Downs 
Station (A. L. Jack). 
Qernis — FEBNA, Bruguiere, 1789. 
(Tab. Encyclop. Method., PI. 175.) 
Peeita GiOANTEA, Moore. 
Perna gigantea, Moore, Quart. Journ. Geol. Soc., 1870, xxvi., p. 249. 
Sp. Char. Shell very large, measuring six and a quarter inches broad by five and a 
half inches in length, flattened ; umbones depressed and rather produced ; anterior byssal 
area rounded ; hinge-line rather oblique, extending one-third the width of the shell ; 
posterior end oblique, rounded, and folding tow'ards the ventral margin, which, with the 
anterior end, is rounded. {ALoore.) 
Obs. P. gigantea was associated with Lingvda ovalis, and a Mytilus, both 
species characteristic of the Wollumbilla blocks. The shell has not been figured, nor 
has it occurred to me in any of the Collections examined. 
• Loo. Wollumbilla (The late Bev. W.B. Clarke). 
Genus — INOCEBAJICS (J. Soicerhy, 1814, m.s.), Parkinson, 1819. 
(Trans. Geol. Soc., v., p. 55.) 
Obs. The genus Inoceramus was proposed and described in a Paper read before 
the Linnean Society of London on Ist November, 1814, by the late Mr. .lames Sowerby, 
entitled “ On a Fossil Shell of Fibrous Structure,” Ac. The description w.as published 
in December, 1822 ;* but, in the meantime, between the dates of reading and publication 
of Sowerby’s paper, Parkinson published a description — viz., in 1819 f — which must, 
therefore, be accepted as the real date of the publication of Inoceramus, and not 1814, 
as is usually given in works. 
* Trans. Linn. Soc., xiii., Pt. 2. 
t Trans. Geol. Soc., v., p. 55. 
