97 



Magasella cumingi, Davidson. 



Terebratellaf?) cumingii, Davidson, Ann. and Mag., Nat. 

 Hist. 1852, 2nd ser., vol. ix., p. 368, and Proc. Zool. Soc, Lond., 

 1852, p. 78, pi. xiv., figs. 10-16. 



TerebratuJa (BouchardiaJ cumingii, Reeve, Conch. Icon., 

 1861, pi. viii., fig. 30. 



Magasella cumingii, Davidson, 'Challenger" Rep. Zool., 

 vol. i., 1880, p. 48. 



M. cumingi, Davidson, Proc. Zool. Soc, Lond., 1886, p. 97, 

 sp. 54, pi. xvii., figs. 23-32. 



Magas cumingi, Davidson, Angas, Proc. Zool. Soc., Lond., 

 1867, p. 935, "deep water outside Port Jackson Heads." 



Terebratula (BouchardiaJ fibula, Reeve, Conch. Icon., 1861, 

 pi. viii., fig. 30. 



Dredged in both gulfs and both straits at 12 fathoms, 

 75 alive; at 13 fathoms, 6 alive; at 15 fathoms, 51 alive; 

 at 17 fathoms, 83 alive; at 20 fathoms, very many; at 22 

 fathoms,, great numbers; at 27 fathoms, 2 alive; at 30 

 fathoms, several dead ; at 35 fathoms, off St. Francis Island, 

 2 alive; at 40 fathoms, off Beachport, 15 small, dead; and 

 at 49 fathoms, 24 small, dead ; at 55 fathoms, off Cape Borda, 

 7 small, dead ; and at 62 fathoms, 27 small, dead ; at 90 

 fathoms, Cape Jaffa, 10 minute; at 110 fathoms, Beach- 

 port, 20 perfect (several alive up to full-grown); at 130 

 fathoms. Cape Jaffa, 26 minute and up to adult; at 150 

 fathoms, Beachport, 19 perfect, small, and 15 valves; and at 

 200 fathoms, 7 dead, very poor. 



Magasella exarata, n. sp , Verco. PI. xxviii., figs. 6 to 8. 



SheJl small, solid, oval, compressed dorso - ventrally, 

 white. Dorsal valve nearly flat, with a shallow median fur- 

 row widening anteriorly; slightly convex longitudinally and 

 transversely ; lateral margin sinuous, convexo-concave from 

 behind, and convex in front to correspond with the median 

 sinus. Ventral valve twice as deep as the dorsal, uni- 

 formly convex longitudinally. Beak projecting considerably 

 beyond the hinge line, solid, slightly curved dorsally. Fora- 

 men triangular, completed in front by the dorsal valve, 

 rounded behind, and not extending to the end of the beak; 

 bounded at the sides by a solid, stout, low lamina. Sculp- 

 ture, numerous axial diverging riblets, increasing by inter- 

 calation, with concentric riblets, somewhat irregular in size 

 and distance. Border internally plicately toothed. The 

 hinge teeth in the ventral valve are very low and small 

 and tubercle -like. In the dorsal valve the laminae on the 

 inside of the tooth sockets are prominent and solid. From 

 the anterior end of their bases tw T o short stout processes pro- 

 ject forwards ventrally, and converge without uniting. Two 



