74 PHYLOGENY OF FUSUS AND ITS ALLIES. 



volution and there are four or five ribless whorls with faint raised spiral 

 lines of primary and secondary type. 



The very slight depression of the suture gives this shell a Pleur- 

 otonia-like aspect. The end of the canal is slightly reflexed. 



The figure given by Petit shows only primary and secondary 

 spirals, i. e., a single intercalation of spirals in a large specimen of over 

 eleven whorls. 



Localities and Habitat: Coast of Gulf of Mexico (obtained by 

 Captain Coue (Petit). Between Tampa and the Dry Tortugas in 27 

 fathoms on sand (Nat. Mus. 93654) ;' Gulf of Mexico, in 26 fathoms on 

 fine white sand (Nat. Mus. 83572). 



FUSUS (?) DILECTUS A. Adams. 



1855. Fusus dilectus A. Adams, Zool. Proc, 221. 



1881. Fusus dilectus A. Adams, Tryon. Man. Conch., vol. Ill, p. 68 and 227, pi. 

 85, fig. 590. 



A dead specimen in the collection of the National Museum with 

 barnacles growing on its outer lip has been identified with the above 

 species. It has the same aspect as the preceding, but differs in detail. 

 It is somewhat stouter and less tapering. The protoconch is similar. 

 The first whorl of the conch is worn, but appears not unlike that of 

 the preceding species. The second third and fourth whorls have three 

 strong sharp spirals in the center of the whorl, and an additional one 

 on either side close to the suture. Intercalation of spirals occurs on 

 both sides of the central spirals, and soon becomes compound. The 

 ribs disappear in the later whorls, but the striae continue. The shoulder 

 is more concave than in F. couei and the center of the whorl has a more 

 angulated appearance. The secondary and even the tertiary spirals 

 become strong, and all are cancellated by the strong lines of growth, 

 much as in F. halistreptus. 



This species may represent a parallel to F. couei from another Fusus 

 stock. The specific identification is doubtful. 



Locality: Moluccas (Nat. Mus. 19314). 



FUSUS CERAMIDUS Dall. 



1889. Fusus ceramidus Dall, Blake Moll., vol. 2, p. 171. 



This is not a typical Fusus, as its form is rather short with a short 

 anterior canal. In this respect it comes nearest to the Mediterranean 

 species of to-day. 



The protoconch is typically Fusoid, the apical portion obliquely 

 elevated, the last portion with fine riblets and ending in a varix. The 

 first two whorls of the conch are non-angular, although two central 

 strong spirals are present. Beyond this the whorls become angulated. 

 The ribs are far apart and sharply angulated by two spirals; the third 



