PHYLOGENY OF FUSUS AND ITS ALLIES. 57 



FUSUS CLAVATUS (Brocchi). 



(Plate VIII, fig. 15, see also fig. 13.) 



1814. Murex clavatus Brocchi, Conchiologia fossile siibapennina, T. 2, p. 418, 

 lav. VIII, fig. 2. 



This shell diflfcrs from F. longirostris chiefly in its rounded whorls 

 which persist throughout. The whorls are round and furnished widi 

 simple rounded ribs, which in the young extend from suture to suture, 

 but in the adult are only marked upon the periphery. The first three 

 or four volutions have simple spirals, though a single intercalated spiral 

 appears next to the suture in the third volution. The primary spirals 

 are sharp and pronounced, the secondary ones very much smaller. In 

 the last whorl very fine tertiary spirals appear. 



Several varieties may be recognized. In Brocchi's type specimen 

 the ribs appear to continue to the end of the final whorl, while the 

 shoulder becomes slightly depressed. In a number of specimens from 

 Asti and Castelarquato the whorls continue round, but the ribs dis- 

 appear on the last volution, the spirals, however, remaining strong 

 (fig. 15). In other specimens the shoulder becomes more depressed, 

 the spirals stronger and the whole shell more robust (fig. 13). This 

 leads to F. ctritscus. 



Localities: Asti (M. C. Z. 1213, 1215) ; Stazzano, Italy (M. C. Z. 

 1225); Castellarquato (M. C. Z. 1221). 



Horizon: Pliocene (?), Subapennine stage. 



The following variety was described (but not figured) by Basterot: 



FUSUS CLAVATUS var. 3 Basterot. 

 1825. Fusus clavatus var. /? Basterot, Mem. Soc. Hist. Nat. Paris, t. 2, p. 63. 



"Testa transverse cingulata, striis filiformibus fere duabus inter- 

 positis ; carina nulla ; anfractibus rotundatis." 



..." La var. /? se trouve aux environs de Bordeaux." 

 This variety is the one figure on Plate VIII, fig. 15, while the variety 

 figured in fig. 13 (var. ^ ) is accelerated. The type specimen repre- 

 sents an intermediate form. 



FUSUS ETRUSCUS Pecchioli. 



(Plate VIII, fig. 14.) 

 1862. Fusus etruscus Pecchioli, Di un nuovo fossile delle Argille Suhapeiinine, 

 Firence (with plate). 



This large and robust species differs from F. clavatus in the angu- 

 lation and nodulation of the whorls, and the very coarse spirals. The 

 ribs persist through the last whorl, but are more of the character of 

 undulations. Where crossed by the strong spirals they are coarsely 

 nodulated. Lip strongly Urate. 



