32 PHYLOGENY OF FUSUS AND ITS ALLIES. 



(M. C. Z. 887, var.) ; Indo-Pacific (Nat. Mus. 91740, var.) ; no locality M 

 given (M. C. Z. 886, 888, 880). ^ 



FUSUS NODOSO PLICATUS Dunker. 



(Plate III, fig. 10.) 



1867. Ftisiis nodoso-plicatus Dunker, Nov. Conch. Moll. Mar., p. 99, pi. 33, 



figs. 3, 4. 

 1881. Ftisus tuberculatus var. nodoso-plicatus Tryon, Man. Conch., vol. Ill, 



p. 54, pi. 34, fig. no. 



This species is of the general form of F. tuberculatus, but larger 

 and more robust. The protoconch and early whorls of the conch are 

 broken away in the only specimen seen. Between four and five of the 

 remaining whorls are round, with round ribs and uniform spirals. 

 Intercalated spirals appear in the second or third whorl. Two of the 

 central spirals finally become strengthened, producing a double carina- 

 tion, a feature not uncommon in F. tuberculatus. An increased 

 strengthening of the lower of these spirals produces the normal keel 

 which becomes nodose where crossed by the ribs. These latter grad- 

 ually disappear from the shoulder, which becomes flatter and flatter. 

 Below the keel they remain in force somewhat longer, dying .. , 

 however, downwards. The spirals are strong, and compound inter- 

 calation occurs while the shell is still young. 



Some of the very robust individuals of F. tuberculatus resemble 

 this species closely. This resemblance is even found in the coloration, 

 which is similar in both species. The present species may be regarded 

 as a vigorous descendant of F. tuberculatus, characterized by an ac- 

 centuated development of the features of that species. Nevertheless 

 it is more than a variety of F. tuberculatus as Tryon considers it. 



Locality: Yenosima, Japan (M. C. Z. 894, Morse coll.). 



FUSUS NODOSOPLICATUS var. LISCHKII var. nov. 



(Plate III, fig. 5.) 

 1869. Fusus nodosoplicatus var. Lischke, Jap. Meer. Conch., pt. i, p. 34, pt. 2, 

 pi. 3, fig. 6. 



This variety was first described by Lischke, who gives the following 

 characteristics as distinguishing this form from the species. The 

 characters of the young shell are identical with those of the typical 

 form down to the sixth or seventh whorl. After this in the typical 

 form the shoulders become flatter, and the ribs increase in thickness, 

 forming tubercles on the shoulder angle. "In the variety, however, 

 the ribs and tubercles scarcely increase in thickness in the seventh and 

 eighth whorl, and after that begin to disappear. The two final volu- 

 tions show only scattered indications of them, while the convexity of 

 these whorls remains uniform, the last of these being well rounded." 



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