486 NOTES ox SOME RECENT MOLI.TJSCA, 



a large piece of sponge is eighteen lines lon<r, thirteen lines broad, 

 at the posterior end finelj' wrinkled, anterior end smooth. It is 

 quite distinct in ever}^ respect and need never be confused with 

 Saxtcava australis. 



9. Mercexaria paijcilamellata. 



Mcrcenaria 2J((iicilamell((ta, Dunker, Novitates, Conchologicpe 1858, 



p. 52, pi. 16, fig. 10, 11 — 12. Fenus alatus, Eeeve, Conch. 



Icon., 1163, pi. 18, fig. 83. Chione {Circomplialus) alatus, 



Angas, Proc. Zool. Soc, 1867, p. 921. CaJlista Victorice, 



Tenison-Woods, Proc. Eoy. Soc, Tas., 1876, p. 171, 



JIah. New Holland {Lesclihe). Port Jackson Heads, AVoUon- 



gong. Port Stephens and Lake Macquarie, New South Wales 



{Angas, Eargraves, Brazier). Circular Head, North Tasmania ; 



Cloudy Bay on the South of Bruny Island and Frederick Henry 



Bay, Tasmania {Rev. II. D. Atlcinson). Swan Eiver {Eeeve) the 



New Holland of the old authors. 



The figures given of the adult specimf ns by Dr. Dunker are 

 very fine of this nearly smooth species, broadly rayed with pale 

 brown, with a few erect ridges at the posterior side. The young 

 shells are more or less distinctly ridged throughout. One specimen 

 that I have is more like Chione lamellata,, having six distinct ribs 

 and terminating at the anterior end in long points or prongs and 

 canaliculated on the upper side, prongs four lines long, length of 

 specimen fourteen, breadth ten lines ; another valve I have has 

 the prongs in the centre of the ribs ; two more specimens have 

 four lameUated ribs and two elongated canaliculated erect prongs 

 on each rib at the anterior end, length eleven, breadth seven lines; 

 one specimen with two small ribs wide apart each rib with three 

 prongs slightly curved down at the end : one nearly in the centre, 

 the other two near the anterior end and terminating in a broad 

 lamellated prong at the posterior end, length six, breadth four 

 and a-half liups. One specimen with four prongs on the edge of 

 a very indistinct rib : one lamellated jirong at the posterior end, 



