BY C. HEDLEY. 731 



Asaphis contraria, Deshayes. 



Psammobia contraria, Deshayes, Catalogue des Mollusques de 

 l'lle de la Reunion, 1863, p. 11, PI. i., ff. 20-21. , 



(Plate xlviii., figs. 4-8.) 



Nearly forty years ago Deshayes received a single right valve 

 of this remarkable shell from Bourbon. For its reception Dr. 

 von Martens afterwards instituted the section Heteroylypta* 

 Mr. J. Brazier has handed to me a specimen with both valves in 

 natural apposition, and slightly larger than the type, which he 

 collected in shell sand at the mouth of the Nambuccra River, 

 N.S.W. The extreme rarity of the shell, its unexpected occur- 

 rence in Australia, and the brevity of published information are 

 sufficient reasons for again figuring and describing it. Its in- 

 clusion in Asaphis is due to Dall.f 



Shell small and thin, oblong, rather compressed, equivalve, a 

 little inequilateral, slightly gaping behind. Colour pale yellow. 

 Umbones sharp, almost touching, transversely directed. Liga- 

 ment short, elevated above the shell. Lunule minute, sharply 

 excavated, lanceolate. The regular growth lines, which can be 

 traced everywhere, are masked by an elaborate superficial orna- 

 ment like the pattern of Cytherea pectinata. The tip of the beak 

 has a few regular, concentric ridges, past which the sculpture is 

 differentiated into four areas : a small anterior, a large medio- 

 anterior, a still larger medio-posterior and a small posterior. The 

 anterior panel, limited by an imaginary line drawn from the beak 

 to the middle of the anterior margin, has a few, widely separated, 

 well developed, longitudinal ridges. To form the next panel each 

 ridge turns at right angles, narrows to a fine thread and runs a 

 direct course to the ventral margin; in this medio-anterior panel 

 there are about twenty of such narrow, close, oblique, raised 

 threads, which become smaller and closer as they approach the 



*Martens, Moll. Maur. 1880, p. 331. 

 tDall, Trans. Wagner Inst, iii., pt. v. 1900, p. 981. 



