62 PHYLOGENY OF FUSUS AND ITS ALLIES. 



out a greater part of the life of the individual. The ribs become 

 obsolete on the fifth or sixth whorl of the conch, after which the 

 whorls are only marked by faint spirals. On the ribless whorls the 

 lines of growth are of about equal strength with the spirals, thus pro- 

 ducing a cancellated appearance. 



Localities: Sicily, Palermo (Coll. Wag. Free Inst. Sci. 4673) ; no 

 loc. (M. C. Z. 1226) ; Torino (Bell, et Mich.) ; Voslau and Vienna 

 Basin; rare (Homes); Lapugmy (Neugeboren). 



Horizon: Lower Tegel, Miocene of Vienna Basin (Homes), 

 Pliocene of Italy. 



Homes figures a number of specimens from the Vienna basin under 

 this name. In some of these the carina persists longer, thus recalling 

 the figure of F. cinctus given by Bellardi and Michelotti. 



FUSUS CINCTUS Bellardi and Michelotti. 



1840. Fusus cinctus Bellardi and Michelotti, Saggio Orittografico, p. 12, tav. 



I, fig- IS- 



This is apparently a closely related species which occupies an inter- 

 mediate position between F. rostratus and F. semirugosiis. It retains 

 the carina or keel in all but the final whorl. The relation of these two 

 species to F. rostratus- was pointed out by the authors cited. 



Locality: Asti. 



H orison: Pliocene. 



Recent Species of the Fusus Rostratus Series. 



FUSUS FRAGOSUS Reeve. 



(Plate VII, figs. 12, 13.) 

 1848. Fusus fragosus Reeve, Iconica, pi. 19. fig. 71. 

 Compare Fusus rostratus Reeve, Iconica, pi. 14, fig. 55. 

 Compare Fusus rostratus Tryon, Man. Conch., vol. Ill, p. 61. 



This is the most primitive existing member of this series. It is 

 even more primitive than any of the species so far described from the 

 Pliocene beds, though it is to be presumed that this species existed in 

 Pliocene times. 



The protoconch is less elevated than in the coins series, the whorls 

 being somewhat compressed. The early portion is smooth, the later 

 furnished with smooth vertical riblets. The total length of the proto- 

 conch is about one and one half volutions. The whorls of the conch 

 are round in all stages, furnished with rounded ribs which in the earlier 

 whorls are less than their width apart, but on the body whorl are 

 separated by interspaces nearly twice as wide as the ribs. The spirals 

 are strong and nearly uniform in the early whorls ; the central one in- 

 creases in strength in the later whorls, but never becomes strong enough 

 to produce an angulation. Intercalated spirals appear in the fifth or 

 later whorls of the conch. 



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