142 PHYLOGENY OF FUSUS AND ITS ALLIES. 



Oppenheim says of this species : "Die Form steht in der Mitte 

 zwischen CI. N'ocr einer, und CI. longceviis Sol. (= CI. scalaris Lam., 

 Cossmann, Cat. IV, p. 172) anderseits ; von der ersten Art besitzt sie 

 die etwas schwacheren aber immer noch hervor tretenden Spiralen, 

 von der letzten den rampenartigen Kiel an den letzten Windung-en." 



Tournouer's figure shows a less pronounced type. The spirals 

 are stronger but the shelf is less projecting. The spiral depression 

 below the shelf exists, however, and the preephebic stages are nocr-Hke. 



This is an important and common species in the fauna of the 

 "Blaue Margel" near Pau on the borders of the Pyrennees — 

 degli Orti, Val Orcagna, Castelcies, Onigo) Northern Italy (Oppen- 

 heim). 



COSMOLITHES gen. nov. 



The species of this genus are fusoid shells with ribbed and spirally 

 striate whorls which in some species become smooth toward the end. 

 The protoconch is depressed and naticoid, consisting of about one 

 and one half volutions. The greater portion is smooth, but toward 

 the end are a number of fine, smooth and uniform, vertical riblets. 

 A moderate varix marks the end of the protoconch. Columella plaited 

 with one prominent plait, and in some specimens with an additional 

 fainter one. 



This genus differs from Rhopalithes in its depressed naticoid proto- 

 conch, with numerous riblets, and in its single strong plication. The 

 differences are constant and important. These features indicate some 

 relation to Fasciolaria. 



Genotype: Fiisus iiniplicatus Lamarck. 



COSMOLITHES UNIPLICATUS (Lamarck). 



(Plate IX, figs. 13, 20; Plate XIII, figs. 1-3.) 

 (Figures 22 and 23.) 

 1S03. Fusus uniplicattis Lamarck, Ann. du Mtis., T. II, p. 385. 



1823. Fusus uniplicatus Lamarck, Receuil Planch. Coq. Foss. Env. Paris, pi. 4, 

 figs. 3 a, b. (Ann du Mus., pi. 6, fig. s a, b.) 



1824. Fusus uniplicatus Deshayes, Coq. Foss. Env. Paris, p. 536. 



The protoconch of this species consists of one and one half volu- 

 tions, is depressed, naticoid, the apex minute, but gradually enlarging 

 throughout. The last portion of the protoconch is strongly ribbed, 

 with close-set smooth vertical ribs. Toward the end faint spirals in 

 the form of crenulations appear between the ribs but do not cross 

 them. 



The conch begins abruptly with strong revolving spirals, and 

 rather indefinite rib-like folds or undulations. These are far apart, 

 but in the later whorls they become more prominent and defined. 

 During the nepionic stage they are uniform from suture to suture, but 



