-Ti;.. l-i IDA. 



Genus FUSlsi'lHA. Hall. 



la part JfavAuonta and Subulitr* of several author*. 



i. HAI.I-. 1871, Twi-nty -fourth Rep. N. Y. St. Mus. Nat. Hist., p. 219. 



'"" 



Slu'll fusiform, spire elevated; whorls generally convex, with distinct sutures, 

 her times nearly flat with shallow or enamelled -utures; aperture longitu- 

 dinal, elongate ovate or subelliptical, acuminate above, produced below, forming a 

 sul>riinate canal; outer lip sharp, its edge straight from the suture almost to the 

 involute extremity of the coluraella; columella nearly vertical, slightly twisted, 

 simple, thin; test varying in thickness, sometimes heavy with indications of broad 

 revolving bands (fcolor bands); exterior surface smooth, or with rows of minute 

 punctures arranged in either revolving or longitudinal lines. Type, F. ventrieosa 

 1 1. ill, which seems to be a variety of F. injiata Meek and Worthen sp. 



The principal difference between this genus and Subulites, Conrad, lies in the 

 basal part of the aperture. This is relatively wider and more truncated in that 

 genus. On page 1070 we give other details that may aid the student in discrimi- 

 nating between thd two genera. These may be supplemented with the remark that 

 the shell is perhaps always heavier in Fusispira, giving deeper and open sutures in 

 clean casts of the interior. 



1 i SISPIKA ISFLATA Meek and Worthen. 



PLATE LXXX. fioa. 17 and 1. 



Subuliu* irtfatui MEEK and WOKTHEN, 1870, Proc. Acad. Nat. Scl. Phlla., p. 47; also 1875, Geol. Sur. 



III., vol. Tl, p. 406. 

 Fioiipira wntriooM HALL, 1871, Twenty-fourth Rep. N. Y. St. Hun. Nat. Hist., p. 229, pi. vui, fig. 6; 



WnrrrucLD, 1882, Geol. Wla , vol. Iv, p. 245, pi. iz, fig. 2. 



Casts of the Interior comparatively short-fusiform, ventrlcose, consisting of six or seven convex 

 whorls, the apical angle'expanding with each whorl after the third or fourth; average apical angle about 

 00. Volutions strongly convex, the last very ventrlcose and constituting over two-thirds of the entire 

 bight of cast; under side of whorls, as seen along the whole inner side of the aperture, strongly concave, 

 the upper half of the outline meeting the vertical lower or columellar half at an angle of about 135 In the 

 typical form and about 125 in the variety wntrieoM,- suture distinct without being channelled or 

 Impressed. Aperture oblique, narrow, the length more than twice the width and a little more than half 

 I entire length of the cast; base abruptly rounded, forming a shallow canal; outer lip sharp, directed 

 -lightly forward In the middle; columella vertical, nearly straight, less than half the length of the aper- 



rery slightly twisted. Surface of casts smooth, of the shell unknown. 



This species is very constant In most respects, and yet a recognizable and apparently persistent dif- 

 ference obtains between the specimens of i ; ira bed and thow> of the overlying Madura bed. In 



the latter, namely, and these agree most closely with the Wisconsin typesof F. twnJrioMa, the under -j,|. ,.r 

 the body volution Is slightly more ventricose and rounds in more abruptly where It joins the columella. 

 forming a deeper angle than In the typical form of the species. In Hall's figure, however, the angle Is 

 deeper than we have seen It. and, considering the constancy of the part In other specimens, we are Inclined 

 to believe that It was drawn deeper than It should be. 



formation and locality. Rather common In th<- Fusisplra bed at Hader, Aspelund, Wykoff and other 

 localities In Ooodhue and Flllmore counties; also in the Maclurea bed (var. oenlrtooM) at - 



