PIIYLOGENY OF FUSUS AND ITS ALLIES. 'J'J 



Localities: Rcthcuil, Soissons, Cuise-Lamotte, Cuise St. Gobain, 

 Paris Basin. 



Horizon: Sables infcricurs. Lower Eocene. 



FUSUS MULTISPIRATUS v. Koenen. 



1856. Fustis unicarinattis Beyrich, Zeitschrift d. Deutsch. Geol. Gesellsch., p. 



80, pi. VII, fig. 6. 

 1889. Fusus multispiratus v. Koenen, Nord-deulsch. Unter Oligociin, Lief, i, p. 



174, pi. 14, fig. 56. 



Von Koenen describes tlic protoconch of this species as consisting 

 of one and a half smooth swollen and strongly arched volutions, the 

 apex "abweichend gewunden iind eingewickelt." In the absence of 

 illustrations it is somewhat difficult to understand the exact meaning 

 of these words but they suggest the typical Fusus protoconch. The 

 smooth portion is succeeded by a half volution which is ribbed with 

 eight fine riblets. The protoconch is said to be similar to, though 

 smaller than, that of the French specimens (F. unicarinatiis?) from 

 Cuise. 



The sculpture of the conch appears abruptly, consisting of four 

 strong spirals, the third of which (from above) is the strongest. The 

 earliest whorls are round, and the ribs extend from suture to suture. 

 The whorls later on become angular, the shoulder flattened, and the 

 ribs obsolescent at the sutures. The central spiral forms a carina, 

 which is strongly noded where crossed by the ribs. 



Localities: Biere; Unseburg; Lattorf; Lethen; North Germany. 



Horizon: Lower Oligocene (von Koenen). 



This appears to be a true Fusus, representing the torcuiiius type of 

 the modern series among the earlier Tertiary. 



FUSUS ERECTUS von. Koenen. 



1889. Fusus crcctus v. Koexe.x, Norddculsch Unleroligocan, Lief. I, p. 176, pi. 14, 

 figs, ja, b; 8a, b, c. 



This small species appears to be a true Fusus judging from the 

 description. The protoconch is described as smooth and " blasig auf- 

 getrieben" of one volution and a half, followed by a quarter volution 

 with four smooth riblets. The ornamentation of the conch appears 

 abruptly, with three spirals on the rounded whorl, the central spiral 

 being the strongest. Additional spirals appear a little later, and inter- 

 calation occurs in the adult. Ribs strong and far apart in the adult; 

 interspaces two to three times their width. The whorls remain round 

 to the end. 



Von Koenen compares this species with a variety of F. aciculatus 

 from ]\Iouchy, 



Localities: Lattorf ; Calhe ; Atzendorf ; L'nscburg ; North Germany 

 (von Koenen). 



Horizon: Lower Olisfocene. 



