100 COIIBCTIOIIS I'EOM MEIA2raSIA. 



and bifid, and two in the left, of which the anterior is the larger a,nd 

 bifid. A single lateral tooth occurs in the right valve' on each side 

 not far from the cardinals, with a groove between them and the 

 margin. Left valve with a sKght tooth-like projection on the mar- 

 gin on each side fitting into the grooves in the other valve. The 

 pallial sinus is large and deep. Internal cartilage minute, narrow, 

 oblique, posterior to the cardinal teeth. External ligament small. 

 The largest specimen measures 13 millim. by 9g. T. alba of Wood 

 is somewhat like this species, but is more acute posteriorly, the 

 detail of its dentition is different, and the cartilage larger. 



27. Mactra eximia. 

 {Deshayes) ; Meeoe, Conch. Icon. fig. 31 (rayed variety). 



Hah. Port Denison, Queensland ((7oppm5r«r) ; Port Curtis, More- 

 ton Bay (coll. Ouming) ; N.E. coast of Australia (Brit. Mus.). 



There are altogether eight specimens of this species in the Museum, 

 three of them being ornamented with numerous reddish rays, and 

 the remaiuing five uniformly white beneath the greyish and yellowish 

 epidermis. 



28. Mactra producta, var. 



Spisula producta, Angas, Proc. Zool. Soc. 1867, p. 909, pi. 44. fig. 7. 



Hah. Port Jackson (Angas and Coppinger). 



The three shells dredged by Dr. Coppinger are probably a variety 

 of this species. They are aU small, apparently immature, and differ 

 from the types presented to the Museum by Mr. Angas in being 

 less produced posteriorly. They are proportionally longer from the 

 umbones to the ventral margin, which exhibits a very faint incurva- 

 tion near the hiuder extremity, and the posterior dorsal slope is a 

 trifie more arcuate. 



29. Mactra (Oxyperas) coppiiigeri. (Plate VII. figs. D-D 2.) 



SheU transversely elongate, triangular, a little inequilateral, 

 rather compressed, thinnish, narrowly gaping posteriorly, smooth 

 towards the beaks, concentrically plicately ridged elsewhere, white, 

 covered with a pale yellowish epidermis, spotted somewhat sparsely 

 throughout with brownish dots, and ornamented on the dorsal areas 

 with cross lines of a deeper brown, and with a large patch of the 

 same colour on the hinder slope of each valve. Umbones moderately 

 acute, not large, inclining towards and situated a trifle in advance 

 of the centre. Lunule sunken, not circumscribed by acute edges, 

 extending more than halfway down the anterior slope. Posterior 

 area as deep as the lunule and a trifle longer, smoothish, not much 

 affected by the terminations of the concentric ridges. Two lateral 

 teeth on each side in the right valve, separated by a deep groove 

 quite approximated to, the cardinal teeth in front and the cartilage- 

 pit behind. The latter is large, deep, and located posterior to the 

 beak. The cardinal tooth is small, insignificant, bounds the ligament, 

 and has a cross piece above it immediately beneath the apex of the 



