24 Bulletin 29 188 



According to Sowerby the columella of T. bipartita is 

 smooth, and Dall also says the pillar of this form seems to be 

 simple and smooth. But our specimen which was sent by Pro- 

 fessor Gabb to Cornell (Museum No. 7665) is broken away con 

 siderably at the aperture and this reveals very definitely two 

 sharp plications on the columella; — but far within, at least a 

 quarter of a revolution, so that they could not been seen were 

 the shell unbroken. The fact that the columella is biplicate in 

 T. bipartita adds strong evidence to the relationship established 

 by Dr. Dall of the three forms T. spirifera, T. oligomitra and T. 

 cirrus with T. bipartita. It seems much more probable that 

 these three, which all have biplicate columellas, are of the bipar- 

 tita group if bipartita itself has two columellar plications. 



Apparently either Sowerby' s specimens were perfect and the 

 folds were completely hidden, or else what seems very probable, 

 his descriptions of the characters of the columella of T. bipartita 

 and his preceding species, T. incequalis, became transposed by 

 some mistake, — for he says* of incequalis, "columella antice bi- 

 plicata" and of bipartita, "columella antice laevi". As a matter 

 of fact, as shown by the figure, our bipartita columella is biplicate 

 like all those of the bipartita group. Our inczqualis series shows 

 that the columella may appear smooth when the shell is com- 

 plete, but it invariably has within one sharp plication. 



The type locality for T. bipartita is Santo Domingo; but it 

 has also been found in the Chipola marls, Calhoun County, 

 Florida. 



Terebra spirifera Dall 



Plate 3, Figures 15, 16 



Terebra dislocata Gabb (in part), Trans. Amer. Phil. Soc, vol. 15, p. 



225, 1873. Not dislocata Say. 

 Terebra (Acus) bipartita (Sowerby) variety spirifera Dall, Proc. U. 

 S. Nat. Museum vol. 18, no. 1035, p. 38, 1895. 



*Ouart. Jour. Geol. Soc., vol. 6, p, 47, 1849, 



