PHYLOGENY OF FUSUS AND ITS ALLIES. 



65 



FUSUS C(ELATUS Reeve. 



(Plate VII, fig. 17.) 

 1847. Fusus coclatus Reeve, Iconica, pi. 8, sp. 35. 



A specimen in the collection of the Philadelphia Academy of Sci- 

 ences probably represents this species. The figured specimen from 

 the collection of the Museum of Comparative Zoology also approaches 

 this species. 



The protoconch is fusoid, somewhat depressed and consists of only 

 about one aiul a third volutions. The last third is furnished with 

 riblets. 



The conch has round whorls throughout, the ribs are rounded, at 

 first less than their width apart, while on the body whorl they are 

 nearly twice their own width apart. The sutures are deep and the 

 anterior canal is slightly flexed. Intercalated spirals appear on the 

 third whorl. The lines of growth form corrugations where they cross 

 the spirals. 



This species is probably to be regarded as a lateral branch from 

 the rostratns stock. 



The relations of these species may be expressed as follows : 



F. ccvlatus. 



Recent. 



Var. carinatus. 



-F. rostratus. 



1 

 F. fragosus. 



Tertiary. 



F. bredw. 

 F. rostratus. 



F. semirugosus. 

 F. cine t us. 



Fusus sp.f 



10. THE FUSUS AUSTRALIS SERIES. 



This is a series of thick-set Fusi which appear to be genetically 



related to F. distans and F. pcrplexus. They are chiefly confined to 



the Indo-Pacific seas, but are represented on the .American coast by 



F . brasilicnsis. 



FUSUS AUSTRALIS Quoy. 



1832. Fusus australis Quoy, Voyage Astrolabe, zool., vol. 2, p. 495, t. 24, figs. 9-14. 

 1847. Fusus cribrihratus Reeve, Iconica, pi. 5, sp. 20. 



The protoconch of this species has not been seen, but that of the 

 closely related F. brasiliensis may be taken as typical of this species as 

 well. 



The conch begins with n^iuidcd wln^rls, the earliest of w.hich have 

 not been seen. The wliorls arc furnished with rounded ribs and the 

 center is marked by two spirals which are more prominent than the 

 others, because somewhat stronger, as well as somewhat farther apart. 



