G72 Systematic Palkoxtolooy — Upper Devoxiax 



ami hut a small or no uiiiliilicus. 'I'liat author, iiowovcr, includes species 

 without uiuhilifus in the foi'iuev genus. 



It seems to the writer that Polytropiis as detined hy Peruer may in- 

 clude more than one irenus and that the possession of a well-nuirked 

 uml)ilicus may prohahly he regarded as diagnostic of it. The s])ecies in 

 question does not ha\e sigmoidal transverse stri;e, while it seems to have 

 the small or closed umbilicus of Cijdonendna to which it is here referred. 



This shell is quite distinct from other species of the genus. It resem- 

 bles C. mvltistriata but differs in much smaller apical angle, in ])earing 

 more distant, stronger. ])roader carina? and in being usually larger. It 

 ahounds in a stratum near the base of the Chemung at Town Creek. 



Occurrence. — Jennings Formation, Chemung Member. Town 

 Creek, 2122, 2228 abundant. 



Collection. — Maryland Geological Survey. 



Cyclonemina CRENULisTRiATA var. OBSOLESCENS u. var. 

 Plate LXVIII, Fig. 5 



Description. — This variety differs from the typical form in lacking 

 revohdng caringe on the upper part of the body volution. 



Occurrence. — Jennings Formation, Chemung MEiiBEU. Town 

 Creek, 2228. 



Collection. — Maryland Geological Survey. 



Cyclonemina multistriata n. sp. 

 Plate LXVIII, Figs. G-lO 



Description. — Shell conical, volutions gradually increasing in diameter 

 to body volution which is ventricose; number of volutions four in ordin- 

 arily preserved specimens. Volutions rounded; suture distinct. Aper- 

 ture oblique. I'mhilicus small. Surface ornamentiMl by 20 or more 

 strong revolving carina^ crossed by fine but distinct transverse stride, 

 which become stronger on crossing carincT, making the latter ajipear as if 

 somewhat nodose. 



Length 25 mm.: diameter 22 mm. 



