209 



Dentalium zelandicum, Sowerby. 



Dentalium zelandicum, Sowerby, Thes. Conch., I860, vol. iii., 

 p. 101, so. 31, pi. ccxxiii., fig. 13. Type locality — New Zealand; 

 Reeve, Conch. Icon., 1872, vol. xviii., pi. ii., fig. 8; Lesson, 

 Conch. Cab. (Ed. Krister), 1896, Band, vi., Abt. 5, p. 15, sp. 23, 

 pi. iv., fig. 4; Pilsbry and Sharp, Tryon, Man. Conch., 1897-8, 

 vol. xvii., p. 70, pi. vi., fig. 81; Murdoch and Suter, Trans. New 

 .Zealand Institute, 1905, vol. xxxviii., p. 304, 110 fathoms off 

 Great Barrier Island. It is from one of these specimens kindly 

 given me by Mr. Suter that mine are identified. 



Dredged in 130 fathoms off Cape Jaffa, 5 good and 12 

 fragments; in 110 fathoms off Beachport, 1 dead ;. and in 

 200 fathoms, 1 fragment large but eroded. 



The radula, pi. xxvii., fig. 7, has the formula 1.1.1.1.1., 

 with a wide low central cusp, a lateral provided with several 

 small denticles at its inner lower part, and an oblong rhom- 

 boidal marginal. 



My largest specimen attains a length of 55 mm., with a 

 width of 6 mm., and has 32 axial ribs, the smaller of which 

 arise by intercalation. A specimen of 20 mm. in length, 

 with about 2 mm. of the apical end unsculptured, has a dis- 

 tinct fissure of 4' 75 mm. long on the convex surface; another 

 of the same size and age shows none ; a third younger still 

 has 4 mm. unsculptured and no fissure. The fissure in this 

 section of Dentalium. appears to be only occasionally and not 

 always present; just as does the appendical tube in another 

 section.- 



Dentalium virgula, Hedley. 



Dentalium virgula, Hedley, Memoirs Austr. Mus., vol. iv., 

 1903, p. 328, fig. 62. Type locality — "Numerous examples were 

 taken in 63-75 fathoms off Port Kembla, in 41-50 fathoms off Cape 

 Three Points, in 54-59 fathoms off Wata Mooli, and in 50-52 

 fathoms off Botany Bay." 



Dredged in 60 and 62 fathoms off Cape Borda, 43 moder- 

 ately good ; in 90 fathoms off Cape Jaffa, 23 alive and many 

 dead and pieces; in 104 fathoms south-west of the Neptune 

 Islands, 7 good, 44 moderate; in 110 fathoms off Beachport, 

 4 alive, 21 dead; in 130 fathoms off Cape Jaffa, 3 moderate; 

 in 150 fathoms oif Beachport, 93 moderate ; in 200 fathoms 

 off Beachport, 4 poor. 



Some examples have slight annular constrictions at 

 intervals of 3 mm. Here the shell is less opaque-white, and 

 the opacity gradually increases anteriorly, as though at the 

 constriction the shell were thinner, representing a more rapid 

 growth after a period of lessened activity or of rest. The 

 appendix is visible in very early life, when the shell is 

 extremely narrow. There seems to be a great tendency to 

 transverse fracture when the shell is nearly filled up by in- 



