niYLOGENY OF FUSUS AND ITS ALLIES. 33 



"Occasionally the earlier volutions have the central spiral accentu- 

 ated into a more or less strong keel. In the interspaces between the 

 spirals occur from one to three transverse lines" (secondary spirals.). 



This variety, which occurs with the species, represents the ac- 

 celerated type of this species. We note the same characters which we 

 have seen in the F. tuherculatus and the F. toreiimus series. The coins 

 type occurs again in this species. 



A small specimen of this variety from Japan (M. C. Z. 895, PI. Ill, 

 fig. 5) has the earliest whorls broken away. All the whorls are 

 rounded, the earlier ones uniformly, the next ones with a bicarinate 

 aspect, which merges into a unicarinate one, without, however, being 

 strong enough to produce an angulation. Finally the carina becomes 

 obsolete, the last whorl being uniformly rounded. Intercalated 

 spirals appear in the third or fourth whorl. In the last whorl the ribs 

 gradually become obsolete, the intercalated spirals at the same time 

 becoming compound. The posterior canal is slightly developed and 

 the lip is lyrate within. This shell represents a young individual, and 

 its earlier whorls agree precisely with those of fig. 10 of the same plate. 



Tlii.s specimen may be said to represent the longicaudns stage of 

 ^^ ■. elopment in this series, bearing the same relation to F. nodosoplicatus 

 that F. longicaudns bears to F. toreumiis. 



Localities: Japan Seas (Lischke) ; Yenosima, Japan (M. C. Z. 

 895, Morse coll.). 



FUSUS PERPLEXUS A. Adams. 



1864. Fusiis pcrplcxus Adams, Journ. Linn. Soc, Bd. 7, p. 107. 



1868. Ftistis iiicoiista)is Lischke, Jahrb. Mai. Gesell., I, p. 115. 



1869. Fusus inconstans Lischke, Japan. Meer. Conch., pt. i, p. 34, pt. II, Taf. Ill, 

 figs. 1-6. 



1831. Not Fusus inconstans Michelin, jMag. Conch., p. 2;^, pi. ;i;i. 



1879. Fusus perplexiis E. A. Smith, Proc. Zool. Soc, p. 202. 



1881. Fusus pcrplcxus Tryon, Man., vol. 3, p. 54, pi. 33, figs. 102-107. 



The Protoconch of this species has not been seen. 



The conch begins with rounded whorls, crossed by rounded ribs 

 and furnished with uniform but strong round or sharp spirals. The 

 tuherculatus (or torcmnus) stage is characteristically developed in the 

 variety described by Lischke as F. inconstans, while the typical form 

 of Adam's species shows the more advanced coins stage of this series. 



Var. NAGASAKII var. nov. 



(Fusus iiicoiisfaiis Lischke.) 

 The typical form figured by Lischke retains its angular whorls to 

 the end. The ribs also continue to the last whorl where they become 

 obsolete. Tubercles, however, continue to the end (Lischke, pi. II, 

 figs. 1.2). The keel of the type specimens is formed by the strengthen- 

 ing of three central spirals similar to that of F. torcu)iius. Accelerated 



