212 



With these were found many specimens of two other 

 forms — one like a very minute Dentalium, of about the same 

 length, much narrower at its posterior end, which is provided 

 with a similiar spine projecting from the convex side. The 

 anterior end is fractured. The other form gradually in- 

 creases to a diameter just about equal to that of the posterior 

 end of the Cadulus, then contracts, and then expands again, 

 and gradually attains the diameter of the middle of the 

 Cadulus ; here it is fractured. These appear to be three pro- 

 gressive stages of its growth — first, as a Dentalium-like shell, 

 which becomes constricted when it reaches a certain age, then 

 begins to form the proper Cadulus shell, from which it sub- 

 sequently breaks off, leaving the tiny projecting spine beyond 

 the line of fracture. 



Type in Dr. Verco's collection. 



Cadulus spretus, Tate and May. 



Cadulus spretus, Tate and May, Trans. Roy. Soc., S. A. ,1900, 

 vol. xxiv., p. 102. Type locality — Port Esperance, Tasmania, in 

 24 fathoms (W. L. May); Tate and May, Proc. Linn. Soc, 

 N.S.W., 1901, vol. xxvi., p. 420, pi. xxv., fig. 52; Hedley, 

 Memoirs Austr. Mus., 1903, vol. iv., p. 328, in 41-75 fathoms off 

 coast of New South Wales ; also 5 fathoms in Dusky Sound, New 

 Zealand; Hedley and May, Records Austr. Mus., 1908, vol. vii., 

 No. 2, p. 113, in 100 fathoms off Cape Pillar, Tasmania. 



Dredged in 55 fathoms north-west of Cape Borda, 5 

 good ; in 62 fathoms north-west of Cape Borda, 36 good ; in 

 90 fathoms off Cape Jaffa, 6 good; in 110 fathoms off Beach- 

 port, 6 good; in 130 fathoms off Cape Jaffa, 18 good; in 

 150 fathoms off Beachport, 20 moderate; in 300 fathoms off 

 Cape Jaffa, 1 poor. These are identical with cotypes sent to 

 me by Mr. May. 



At the following localities and depths a modified form 

 was dredged : — Sixty-two fathoms north-west of Cape 

 Borda, 3 good; in 90 fathoms off Cape Jaffa, 22 

 good; in 110 fathoms off Beachport, 3 good; in 

 130 fathoms off Cape Jaffa, 2 good ; in 150 fathoms 

 off Beachport, 5 good and 3 moderate. These have 

 at one point in their length a sharp annular constriction, 

 beyond which the shell often has a slightly altered axis, and 

 at times a somewhat different curve. The relative length of 

 the two portions varies ; the earlier or the later part may 

 form nearly the whole, or there may be any intermediate 

 proportion. No complete Cadulus similar to C . acuminatus, 

 Tate, was taken in these dredgings. Mr. May says that in 

 the type locality, where several dozen cotypes were taken, no 

 G. acuminatus, Tate, were obtained. Yet the constriction 

 at the anterior end of C. spretus suggests that it is only the 



