Description of New Species of Fossils. 229 



'Genus— FITSISPIRA nov. gen. 



Shell fusifoi'in, imperforate, spire more or less elevated, with 

 rounded volutions ; aperture elongate-ovate or elliptical, produced 

 below, forming a subrimate canal ; columella slightly twistud, with- 

 out folds, peristome sharp. 



Surface smooth. 



Types of the genus, Fimsjnra ventricos'^ and F. terebriformis. 



The shells for which the above generic name is proposed have the 

 general form of Fusus, and particularly the group included under the 

 name Tritonofusus Beck ; being smooth shells with subequal extremi- 

 ties, but the columella is much less twisted, which gives to them a 

 more erect aspect. They differ from Subulites in not being truncate 

 at the base of the columella, and in being destitute of the deep basal 

 notch characteristic of that genus. 



So far as at present known they are confined to the Trenton and 

 Hudson-river periods. 



The two following species described in the Palgeontology of JST. Y., 

 Yol. I, w^ill probably prove to belong to this genus : MurGhisonia vit- 

 tata = Fusispira vittata, and Murchisonia sitbfusifor7nis=^ F. suh- 

 ftisiformis. 



Fusispira ventricosa ?i. sp. 

 Plate 8, fig. 6. 



Shell ventricose, consisting of six or seven volutions, the first three 

 or four slender, the subsequent ones more rapidly expanding and 

 ventricose, giving an unequally increasing spire ; body volution 

 large, occupying two-thirds of the entire length of the shell ; suture 

 distinct, not channelled or impressed. Aperture narrow oblique, 

 modified by the preceding volution and nearly equalling one-half the 

 length of the shell ; columella less than half the length of the shell, 

 slightly twisted, base rounded below, forming a broad shallow canal ; 

 outer lip sharp, directed forward in the middle. 



Length of specimen described two and three-fourths inches; diame- 

 ter of body whorl one inch and three-eighths. 



Formation and locality. In the Trenton limestone at De Pere, 

 three miles north of Green Bay. 



Fusispira ELONGATwe n. sp. 

 Plate 8, fig. 5. 

 Shell elongate fusiform, spire slender and elevated, gradually taper- 

 ing; volutions moderately convex, number unknown, but judging 

 from those remaining there have been at least eight, of which the last 



