PIIYLOGENY OF FUSUS AND ITS ALLIES. II 



In all typical species the last whorl is abruptly contracted below, 

 and continued in a long spindle which is excavated into a long and 

 slender anterior canal, the forward prolongation of the aperture. The 

 columcllar lip is always smooth but lirae are common on the interior of 

 the outer lip. 



In old individuals, or phylogerontic species, a more or less strong 

 posterior canal is formed, which is the result of the upreaching of the 

 upper portion of the last whorl onto the preceding whorl. Externally 

 this canal is indicated by a vertical, subsutural revolving band, the 

 occurrence of which may generally be taken as an indication of accelera- 

 tion in development. 



The species of Fusus are generally but little colored, though the 

 apical portion and the spindle are often uniformly brown. Dark 

 chestnut-colored spots are frequently seen between the tubercles on 

 the periphery of the volution, and these fade out upward and down- 

 ward. A periostracum, with rather strong bristles at the intersection 

 of spirals and growth lines, covers the shell when fresh. 



Type: Miircx coins Linne. 



Range: Eocene to present. 



Distribution: Nearly all tropical and subtropical seas. 



I. EOCENE SPECIES OF FUSUS. 



A. Species of the London and Hampshire Basins. 



FUSUS PORRECTUS (Solander). 



(Plate I, figs. 5, II, 12.) 



1766. Murex porrectus Solander, Foss. Hants. (Brander), p. 21, pi. 11, fig. 36. 

 1818. Fusus rugosiis Sowerby (non Lamarck), Min. Conch., vol. Ill, pi. 274, 



figs. 8 and 9. 



The original description and illustration of this species leaves some 

 doubt as to the exact characters of the species, which can only be 

 settled by reference to the type specimen. However, the shells here 

 identified with this species have characters which separate them from 

 the British representatives of F. aciculatns, its nearest allies. 



The protoconch of this species is obliquely erect, with the apex 

 invested by the second whorl (fig. i). It is smooth for about a 

 volution and a third, after which it is ornamented by rather distant 

 smooth vertical riblcts. which extend from suture to suture. The 

 protoconch terminates abruptly after something over a volution and a 

 half. The ribs and spirals of the conch appear as abruptly. The 

 whorls arc rounded and separated by deeply impressed sutures which 

 give the whorls the appearance of resting loosely one upon the other. 

 The ribs are rounded and strongly cancellated by the spirals, of which 

 there are four or five at the beginning of the conch. This is die most 



