193 THE VOYAGE OF H.M.S. CHALLENGER. 



thin, yellow, roundeclly triangular, with a terminal apex, and scored across with many 

 fine curved lines of increase, altogether much like that of many of the PJcurotomacea. H. 

 2-18 in. B. 0-9. Penultimate whorl, height 0-19. Mouth, height 172 (aperture 0-34, 

 canal 1'38), breadth 0-3. 



Than Fusus pagoda, Less., this is a smaller shell, with a shorter spire ; its carinal crown is a 

 continuous flange, not a series of hollow flat spikes, the whorls are higher between keel and suture, 

 the base is more contracted and compressed, the prickles on the spiral threads of base and snout are 

 much closer, sharper, and higher, the canal in front is much narrower ; finally, Lesson's species has 

 two embryonic whorls, and these stand up much higher than in this. 



The Eev J. E. Tenison Woods, in a very interesting paper (read before the Koyal Society of New 

 South Wales, July 4, 1877, and of which he obligingly sent me a copy) on the Tertiary deposits of 

 Australia, p. 8, refers to a fossil Fusus occurring in the lowest clays of the Australian Tertiary 

 deposits of lower Miocene, or perhaps Eocene, age. Of this Fusus he says that " it is so like the 

 beautiful and delicately spined Fusus pagodus of the Philippines, that it has, I believe, been named 

 Fusus pagodo'idcs by Professor M'Coy." I have not been able to ascertain that this species has ever 

 been published, and having already, before Mr Wood's paper reached me, selected this name for the 

 Challenger species, I have thought it better to retain it, the more so that, should the Australian 

 fossil prove to be the same as the species living in deep water off Sydney, the substitution of another 

 name would be a pity, and would tend to create confusion. 



Since writing the above, and just as this paper was leaving my hands, I received from Pro- 

 fessor v. Martens, with his accustomed kindness, the number of his Conchologische Mittheilungen (vol. ii. 

 pts. 1 and 2), issued for December 1881, containing his beautifully illustrated description of Fusus 

 pagoda, Less. (p. 106, pi. xxi. fig. 4), which he attaches to a new sub-genus of Pleurotoma under 

 the name of Columbarium, enriching the group with a new species Pleurotoma (Columbarium) spini- 

 cincta(ip. 105, pi. xxi. figs. 1—3), got by the German war-vessel " Gazelle," in 76 fathoms, on the same 

 east coast of Australia, at (apparently) a spot distant some 500 miles N. by E. from the place 

 from which the Challenger specimens come. At p. 122, Mr G. Schacko (pi. xxiv. figs. 1, 2) gives 

 details of the radula, on the peculiarities of which the subgenus is mainly based. The opinion of 

 Professor v. Martens is of course of commanding weight ; and if I have not followed him here, it is 

 merely because I see that not Fusus pagodo'idcs alone, but many of the forms grouped under Troplion, 

 will have to share the fate of Fusus pagoda, Less., whatever that may ultimately be. 1 



In the meantime I content myself with calling attention to this increase in the number of those 

 forms which gather round Lesson's remarkable and beautiful species. With this increase in their 

 number, however, there comes no link of connection between them ; for not one of the three species 

 helps to unite the other two, though the Challenger species stands on the whole nearer to Lesson's 

 than v. Martens' species does to either. Pleurotoma (Columbarium) spinicincta, v. Mart., is dis- 

 tinguished by its high conical spire, its small apes, its more numerous carinal spines, its double basal 

 keel, and the sparseness of the muricated threads on its snout. 



1 I have allowed this paragraph of my Preliminary Report to stand. The opportunity I had hoped for of 

 revising this whole group has not come to me. My conviction, however, is that Professor v. Martens' opinion 

 will prove in the main to be the true one. 



